Table of Contents
Oral Presentations
SPC – Second International URSI
Student Paper Competition
ABD – Low Noise Microwave
Generation
C01
– Frequency Converters and Mixers
D01
– RFID Technology and Applications
E01
– EMC Interactions in Complex Systems
F01
– State-of-the-Art Developments in Propagation and Remote sensing
G01
– Open Session and Latest Results I
H01
– Nonlinear Waves and Turbulence in Plasmas
J01
– Low Frequency Radio Astronomy I – (LOFAR, LWA, MWA, GMRT, any other)
A02
– Fractals - Design and Measurement
C02
– Advanced Architectures of High-Performance Power Amplifiers for Mobile
Communications Systems
DB1:
Modeling of High Frequency Devices and Circuits
E02
– Lightning and Related Effects I
F02
– Attenuation and Depolarization in Satellite and Terrestrial Propagation
G02
– Measuring and Modeling the Ionospheric Electron Density Profile
KBE
– Non-ionizing Electromagnetic Breast Imaging
J02
– Low Frequency Radio Astronomy II
CD –
Advanced RF Integrated Circuits
B03
– Hybrid Methods (in memory of Robert G. Kouyoumjian)
CB –
Antenna Channel Interactions for Future Wireless Communications
E03
– High Power and Intentional EMI (in memory of Carl E. Baum)
F03
– Tropospheric Modeling for Radiowave Propagation and Radar Remote Sensing
G03
- Recent Developments in and Coordinated Studies with Incoherent Scatter Radars
H03
– Wave-particle Interactions and Their Effects on Planetary Radiation Belts I
J03
– Technology Development for the SKA Program
K03
– Environmental EMF Exposure Assessment
C05
– Radio Science for Information Security and Social Safety
KT –
Epidemiology of RF and Cancer
B04
– Electromagnetic Field Transformations for Measurements and Numerical Methods
B05
– Theoretical and Numerical Issues in Electromagnetics
DBC
– Signal Processing Antennas
EGH
– Terrestrial and Planetary Electromagnetics
F04
– Active and Passive Remote Sensing of Vegetation (in honor of Roger H. Lang)
G04
– Practical Applications and Techniques for the Use of Ionosonde Data
HT –
Major developments in our understanding of electric antennas in space plasmas
J04
– Space and Moon-based radio astronomy: science and technology
H04
– Wave-particle Interactions and Their Effects on Planetary Radiation Belts II
B06
– Multiscale Modeling and Applications to Composite Materials
CBD –
Vehicular Communications
F05
– Radar Applications: Polarimetric Interferometry, Smart Systems and
Propagation Impairment
G05
– New Science Initiatives on Irregularities and Scintillation using Beacon
Satellites
HG1
– Radio Sounding in Ionospheres and Magnetospheres and Associated Plasma
Phenomena I
J05
– Sun and Solar System Science
K04
– Biomedical Applications: Diagnostic Sensing
CT –
Six-port Wave Correlator Theory and Practical Application to RF Network
Analysis
CHGBDJK
– Solar Power Satellites and Wireless Power Transmission
DT –
RFID Technology and Applications
EB –
Electromagnetic Modelling for EMC
F06
– Remote Sensing of Oceans, Cryosphere and Related Topics
G06
– Distributed Ground and Space-based Observatories for Space Weather Studies
HG2
– Radio Sounding in Ionospheres and Magnetospheres and Associated Plasma
Phenomena II
J06
– Signal Processing, Calibration and Imaging in Radio Astronomy
K05
– Interactions with Human Body and Implanted Systems
DB3
– Metamaterial Applications
AGJ
– Pulsar Timing and Time Transfer
BD2
– Numerical Techniques for Multi-Physics Electromagnetics
CA –
Propagation Measurement Based Performance Evaluation of Advanced MIMO Systems
D07
– Micro and Nano Photonics
E07 –
EMC in Wire and Wireless Communication Systems
G07
– Ionospheric Research for Radio Systems Support
HG3
– Active Experiments in the Ionosphere and Magnetosphere I
K06
– Biological Effects of EMF: Cellular, Animal
AT –
Single Electron Tunneling (SET)
BJ –
Very Large Antenna Arrays for Radio Astronomy
C10
– Wireless Communication Technologies for Standardization
D08
– Nonlinear Optics and Guided Wave Devices
E08
– Surveys of the Electromagnetic Environment
FT –
Remote Sensing, Systems and Applications: Present and Future
G08
– Open Session and Latest Results II
GHE1
– Lightning Induced Effects in the Ionosphere and Magnetosphere, I
HG4
– Active Experiments in the Ionosphere and Magnetosphere II
J08
– Spectrum Management Issues and RFI Mitigation
K07
– Biomedical Applications: Imaging and Brain Mapping
F08
– System Aspects: Antennas, Calibration, and Interference
C11
– Power Amplifier Considerations for Software Radio Systems
DAF1
– Enabling Technologies for Millimeter and THz Wave Applications
E09
– Lightning and Related Effects II
G09
– CAWSES-2 Ionospheric and Thermospheric Campaigns and Results
H09 –
Laboratory Simulation of Space and Dust-related Phenomena
K08
– Biomedical Application: Healing and Therapy
ET –
EMC Measurements in the Time-Domain
JG –
Ionospheric Calibration for Radio Astronomy (in memory of William E. Gordon)
AD –
Optical Frequency Metrology
B11
– Inverse Scattering and Imaging
C12
– Multiple Antenna Technologies for Communication Systems and Radar
E10
– Stochastic Techniques in EMC
FG –
Ionospheric and Tropospheric Effects in Precision GNSS
GT –
Sprites and Energetic Radiation Above Thunderstorms
H10
– Waves as Signatures of Inflowing Plasma Interaction with Solar System Bodies
J10
– Mm and Sub-mm Science and Technology with a Special Focus on ALMA
KAE
– Anatomical Human Models Development and Exposure Assessment
GHE2
– Lightning Induced Effects in the Ionosphere and Magnetosphere, II
B12
– Novel Mathematical Methods in Electromagnetics
C13
– Signal Processing Advances for Cognitive Radio
DF –
Hyperspectral Sensing and LIDAR
E11
– EMC and Signal Integrity
FCA
– Channel Modeling, Measurements and Characterization in Communications and
Remote Sensing
GHE3
– Electromagnetic Effects in Lithosphere-Atmosphere-Ionosphere Coupling
J11
– New Observations and Results
KB –
Uncertainty Management in Numerical Calculation and EM Field Dosimetry
Poster Presentations
Poster:
RFID and Signal Processing Antennas
Poster:
High frequency Devices and Multiphysics Techniques
FP1
– Poster session 1 – Focus: Remote Sensing
Poster:
Metamaterials and Microwave Techniques
SPC – Second International URSI Student Paper
Competition
Session
Chairs: Steven C. Reising, Birsen Saka
Session SPC
Type Oral
Presentation
Schedule Monday,
August 15, 13:00-16:40
Room Sultan 3
A
fiber-based, all-optical system for femtosecond-precision, long-term, timing
transfer and synchronization of electronics and lasers at the kilometer scale
is presented. The system incorporates a fiber polarization controller for
long-term synchronization of remote lasers, and uses an optical timing detector
based on balanced optical cross-correlation. We demonstrate continuous, unaided
timing distribution over 168-hours with 5 fs rms precision over 340 m of fiber.
Also, timing transfer from local to remote laser for 5 hours with 4 fs rms
precision is shown. A study of linear and non-linear effects impacting
performance is presented.
13:20 SPC.2 AN INVESTIGATION OF WHISTLER INTENSITIES ABOVE
THUNDERSTORMS
We
study a penetration of whistlers to the ionosphere. We developed an automatic
method for assigning causative lightning to fractional-hop whistlers observed
on the DEMETER satellite. Processing data from 364 passes of the satellite over
Europe, we found that at nighttime, a mean whistler intensity is approximately
three times larger than at daytime. A maximum of whistler intensity is shifted
approximately one degree from the satellite magnetic footprint owing to the
oblique propagation. Calculations of wave attenuation made using IRI2007 and
MSIS models show very similar result in a ratio of nighttime and daytime
intensities.
13:40
SPC.3 CONFINING THE ANGULAR DISTRIBUTION OF TGF EMISSION
We
present the first constraints on the TGF emission cone, based on accurately
geolocated TGFs. The distribution of the observation angles for 106 TGFs are
compared to Monte Carlo simulations. We find that TGF emissions within an
isotropic half angle >30deg can generate the observations. In addition, 36
events are used for spectral analysis. The result is a significant softening of
the TGF energy spectrum for large observation angles, which is consistent with
a TGF emission half angle <40deg. The constraints 30-40deg indicates that
the electrons which produce TGFs are accelerated in nearly vertical electric
fields.
14:00 SPC.4 SPECTRAL ANALYSIS OF THE AIRY PULSE BEAM
Y.
Kaganovsky, E. Heyman, Tel Aviv University, Israel
The
Airy beam (AiB) has attracted a lot of attention recently because of its
intriguing features such as propagation along curved trajectories in free-space
and the weak diffraction. Here we derive the ultra wide band Airy pulsed beam
(AiPB) which is the extension of the AiB into the time domain. We introduce a
frequency scaling that renders the ray skeleton of the field frequency
independent, thus insuring that the resulting AiPB is non-dispersive and
preserves the intriguing features of the time-harmonic AiB. An exact closed
form solution is derived using the spectral theory of transients (STT).
14:20
SPC.5 ACCURATE PHOTONIC ANALOG-TO-DIGITAL CONVERSION
Photonic
analog-to-digital converters (ADCs) are attracting significant interest due to
promise of overcoming the problem of aperture jitter and improving ADC
performance level by orders of magnitude. This work examines several critical
factors which define the accuracy of an optically-sampled
wavelength-demultiplexed ADC built on a silicon chip using silicon photonic
technology. These factors are the optical power-dependent shot noise, optical
power-dependent nonlinearities due to two-photon and free-carrier absorption in
silicon, and nonlinear transfer function of a silicon modulator. Ways to reduce
the impact of these factors on ADC accuracy are considered.
14:40 Break
G. Safonova, E.
Vynogradova, Macquarie University,
Australia
The
two-dimensional body potential problem is rigorously solved with emphasis on
electrostatics. By the Method of Analytical Regularization, the solution is
obtained from coupled second kind infinite systems of linear algebraic
equations that are effectively solved numerically by a truncation method. A
combination of the fast convergence with fast and accurate computation of the
matrix elements makes the computational routine extremely efficient: in most
cases the computational time measures a few seconds. As an example, the
developed algorithm is applied to a calculation of the capacitance matrix for N
arbitrary profiled charged cylinders surrounded by a grounded cylindrical shield.
15:20
SPC.7 MODEL ORDER REDUCTION METHODS FOR MULTIVARIATE
PARAMETERIZED DYNAMICAL SYSTEMS
K.
Stavrakakis1, T. Wittig2, W.
Ackermann1, T. Weiland11Technische
Universität Darmstadt, Germany; 2Computer
Simulation Technology AG, Germany
Electrodynamic
field simulations in the frequency domain typically require the solution of
large dynamical systems. Model order reduction (MOR) techniques offer a fast
approach to approximate the system impedance with respect to the frequency
parameter. During the design process, it is desirable to vary specified
parameters like the frequency, geometry details or material parameters, giving
rise to multivariate dynamical systems. In this work, multivariate MOR methods
are presented for multivariate parameterized systems based on the finite
integration technique. The methods are applied to numerical examples with both
geometrical and material variations.
M. Tian, A. J. Gasiewski, University of Colorado at Boulder, USA
A
unified microwave radiative transfer (UMRT) model is presented for computing
the thermal radiation from geophysical media comprised of planar multilayer
spherical scatterers of arbitrary electrical size and density. UMRT employs
discrete ordinate-eigenanalysis to solve the vector radiative transfer
equation. Importantly, UMRT inherits the symmetrization, analytical
diagonalization, and factorization techniques from the discrete ordinate
tangent linear radiative transfer (DOTLRT) model devised by Voronovich et al.,
to ensure accuracy, numerical stability, and computational efficiency, along
with Jacobian capability. However UMRT extends the applicability of DOTLRT by
including the dense media radiative transfer theory and linear temperature
profiles within slabs.
16:00 SPC.9 A COMPRESSED SENSING APPROACH TO OBSERVING
DISTRIBUTED RADAR TARGETS
R.
Volz, S. Close, Stanford University, USA
Compressed
sensing, a method which relies on sparsity to reconstruct signals with
relatively few measurements, has the potential to greatly improve observation of
distributed radar targets. We extend the theoretical work of others by
investigating the practical problems of implementing this approach for
distributed targets, first examining a discrete linear radar model suitable for
compressed sensing and then discussing an example of this technique used on
existing data. Potential benefits include higher possible range resolution,
complete filtering of noise without sidelobes or artifacts, and the ability to
identify different Doppler shifts within the same range window of a single
pulse.
16:20
SPC.10 ANTENNA DESIGN AND CHANNEL MEASUREMENTS FOR ON-BODY
COMMUNICATIONS AT 60 GHZ
X. Y. Wu, Y. Nechayev, P. S. Hall, University of Birmingham, United Kingdom
On-body
communication is of increasing interest for a number of applications, such as
medical-sensor networks, emergency-service workers, and personal
communications. This paper reviews 60 GHz on-body communication and its
benefits and challenges. Two novel low profile high gain, end-fire wearable
antennas are then described. Measurements with an experimental phantom and real
human body are presented. Results show antennas achieve good performance close
to a phantom. Shadowing effects and polarisation issues for on-body
communications at 60 GHz are discussed.
16:40 End of the Session
ABD – Low Noise Microwave Generation
Session Chair: Michael Tobar
Session ABD
Type Oral Presentation
Schedule Monday, August 15, 08:00-10:40
Room Dolmabahçe C
08:00 ABD.1 LOW PHASE NOISE MICROWAVE GENERATION WITH
FIBER-BASED FEMTOSECOND LASERS
When
a femtosecond laser is servoed onto an ultra-stable cw laser, its repetition
rate acquire an extreme spectral purity. By photodetecting the pulses, we are
able to generate ultra-low phase noise microwave signals and use it for cutting
edge metrology experiments. We present our past and present work to generate
microwave signal with very low degradation from the limit imposed by the
reference oscillator, using a highly reliable fiber-based system. The latest
developments involve employing an intra-cavity electro-optic modulator, reduced
relative intensity noise of the laser, and studies of the photodetector
amplitude to-phase conversion.
08:20 ABD.2 CRYOGENIC SAPPHIRE MICROWAVE OSCILLATORS
FOR SPACE, METROLOGY AND SCIENTIFIC APPLICATIONS
We
recently demonstrated a Cryogenic Sapphire Oscillator presenting a relative
short term frequency stability better than 3e-15 for 1 s < t < 1000 s and
achieving 4.5e-15 for one day integration. This CSO incorporates a pulse-tube
cooler instead of a bath cryostat thus eliminating the need for regular
supplies and manual transferring of liquid helium. The advent of reliable and
cryocooled CSO open the possibility to implement such an ultra-stable reference
not only in metrological laboratories with liquid helium facilities but also in
remote sites like base stations for space navigation, VBLI antenna sites, ...
08:40 ABD.3 CHARACTERIZATION OF TIMING JITTER IN
ULTRAFAST FIBER AND TI:S LASERS AND SUPERCONTINUUM
J. A. Cox, A. J. Benedick, F. X. Kaertner, MIT, Cambridge, MA, United States
The
timing jitter of erbium doped, fiber optic and Titanium:Sapphire lasers, both
passively mode-locked ultrafast lasers at 80 MHz, is measured with
unprecedented resolution and bandwidth. Using the balanced optical
cross-correlator timing detector, we found a total integrated timing jitter of
2.2 fs rms [100 Hz, 1 MHz] for the fiber supercontinuum and only 55 as rms [100
Hz, 10 MHz] jitter for the Ti:S laser. This measurement of fiber laser jitter
is an absolute measurement, since the jitter of the fiber laser was measured against
the Ti:S laser, which is negligible.
09:00 ABD.4 OPTICAL FREQUENCY COMBS FOR LOW PHASE
NOISE MICROWAVE GENERATION
An
optical frequency comb locked to a stable optical reference can serve as a
source for microwave signals having very low close-to-carrier phase noise. This
has recently been confirmed by comparing two independent systems, yielding an
absolute phase noise of -104 dBc/Hz at 1 Hz offset from a 10 GHz carrier. The
corresponding timing jitter is 760 attoseconds, integrated from 1 Hz to 1 MHz.
Here we describe the system architecture, as well as technical and fundamental
noise limitations.
09:20 Tea/Coffee Break
09:40 ABD.5 PRECISION NOISE MEASUREMENTS AND
OSCILLATOR FREQUENCY STABILIZATION
E. N. Ivanov, M. E. Tobar, The University of Western Australia, Perth,WA, Australia
This
paper summarizes recent advances in two closely related research fields:
precision noise measurements and generation of low-phase noise microwave
signals. The progress achieved in those fields over the past decade was largely
associated with the applications of microwave circuit interferometry, which is
a powerful noise measurement technique born out of the quest to detect gravitational
waves in the beginning of 90s.
10:00 ABD.6 AN S/C-BAND SIGE HBT DIFFERENTIAL VCO
USING A NOVEL HPF-TYPE RESONATOR COMPRISED OF THE CHIP INDUCTORS FOR A HIGHER
OSCILLATION FREQUENCY
Y. Itoh, Y. Tashiro, Shonan Institute Of Technology, Fujisawa, Kanagawa, Japan
An
S/C-band SiGe HBT differential VCO has been developed for the next generation
wireless radios. It employs a novel HPF-type resonator having a parallel LC
circuit for higher frequency oscillation. The novel HPF-type resonator can be
easily constructed from only the chip inductors by using their parasitic
capacitance. The differential VCO has achieved an oscillation from 3.36 to
4.03GHz, a phase noise of less than -100dBc/Hz at 100kHz offset for VCC=3V and
IC=2.93mA. This is the first report on the differential VCO using only chip
inductors as a resonator element.
10:20 ABD.7 ON THE QUALITY FACTOR OF A LOW-LOSS
PARALLEL-PLATE RESONATOR BASED ON COMPLEMENTARY METAMATERIALS
D. Sjoberg, M. Gustafsson, Lund University, Lund, Sweden
Several
proposals have been made during the last ten years on size-independent
resonators by using metamaterials for phase compensation. In this paper, we
present an estimate of the quality factor of a simple parallel-plate resonator,
based on realistic assumptions such as linear, passive, causal,
time-translational invariant metamaterials, and lossy walls. It is found that
the quality factor of the resonator depends on whether the losses of the
material or the metal walls are dominating: in the former case, there is no
size dependence, in the latter case, the size dependence is similar to a
vacuum-filled resonator.
10:40 End of the Session
Session Chairs: Mats Gustafsson, Gerhard Kristensson
Session B01
Type Oral Presentation
Schedule Monday, August 15, 08:00-09:20
Room Anadolu Auditorium
08:00 B01.1 SPECTRAL ANALYSIS OF THE AIRY PULSED BEAM
Y. Kaganovsky, E. Heyman, Tel-Aviv University, Tel-Aviv, Israel
The
Airy beam (AiB) has attracted a lot of attention recently because of its
intriguing features such as propagation along curved trajectories in free-space
and the weak diffraction. Here we derive the ultra wide band Airy pulsed beam
(AiPB) which is the extension of the AiB into the time domain. We introduce a
frequency scaling that renders the ray skeleton of the field frequency
independent, thus insuring that the resulting AiPB is non-dispersive and
preserves the intriguing features of the time-harmonic AiB. An exact closed
form solution is derived using the spectral theory of transients (STT).
08:20 B01.2 DOES EVANESCENT GAIN EXIST?
We
have investigated the situation where light incident from a passive high-refractive-index
medium is totally reflected off an infinite half space with gain. The question
of whether or not evanescent gain can prevail in this case, has been at issue
for 40 years. We argue that the controversy can be resolved for week gain media
using the Laplace transform, combined with a detailed analysis of analytic and
global properties of the permittivity function of the active medium.
08:40 B01.3 NEW TYPE OF GYROTROPY IN GRAPHENE -
COMPARISON WITH GYROTROPY IN PLASMAS
D. L. Sounas, C. Caloz, Ecole Polytechnique de Montreal, Montreal, Canada
The
gyrotropic properties of magnetically biased graphene are compared to these of
magnetically biased plasmas. Graphene exhibits a significant polarization
rotation phenomenon at frequencies below the cyclotron resonance, where plasmas
do not provide any polarization rotation. At frequencies above the cyclotron
resonance the behavior of graphene is similar to this of plasmas. Graphene
allows the control of its gyrotropic properties via a static electric field,
while keeping the bias magnetic field constant, in contrast to plasmas where
the variation of the bias magnetic field is required.
09:00 B01.4 THE CLASS OF DECOMPOSABLE MEDIA IN
FOUR-DIMENSIONAL REPRESENTATION
TE/TM
decomposition of electromagnetic fields in uniaxial anisotropic media is
generalized applying four-dimensional differential-form formalism by requiring
orthogonality between the field two-form and two given bivectors. Conditions
are derived for the electromagnetic medium allowing the decomposition and found
to define three subclasses of media. The medium dyadics of two of the
subclasses satisfy equations of the second order while that defining the third
subclass satisfies an equation of the first order. Dispersion equations for
plane waves are derived and the corresponding eigenpolarizations are found for
all three subclasses.
09:20 End of the Session
C01 – Frequency Converters and Mixers
Session Chair: Kenji Itoh
Session C01
Type Oral Presentation
Schedule Monday, August 15, 08:00-10:20
Room Dolmabahçe A
08:00 C01.1 KA BAND DIRECT MODULATION USING SUB
HARMONIC MIXER FOR SATELLITE APPLICATION
S. Gupta, B. Batra, N. Kumar, DAIICT, Gandhinagar, Gujarat, India
In
this paper, a KaBand direct modulator using subHarmonic mixer is designed and
analysed. KaBand direct modulator comprises of WilkinsonPowerDivider,
LangeCoupler, SubHarmonic mixer using APDP and Microstrip filters. A subharmonic
mixer operates at half the LO frequency eliminating the need for frequency
doublers, a filter and an amplifier at LO circuit. It provides better
conversion loss and rejects odd harmonic mixing products. Coupled line topology
was selected to get sharp cut off in minimum length of the circuit and for its
compactness. Here QPSK technique used two BPSK modulator systems to get various
advantages related with data rate and bandwidth.
08:20 C01.2 SERIES SWITCHED RESONATOR BASED DUAL-BAND
OSCILLATOR
V. Sharma, R. Yadav, N. P. Pathak, Indian Institute of Technology (IIT), Roorkee, Uttarakhand, India
Multi-band
oscillator plays a crucial role in modern multi-band wireless radios. The
concept of series switched resonator is introduced as a means to achieve
multi-band operation in an oscillator. Using the concept, a prototype dual-band
oscillator was implemented using single transistor. Switching between two
desired frequencies was achieved using a semiconductor diode. The measured
characteristics exhibited adequate phase noise performance while providing
constant power output for both the design frequencies.
08:40 C01.3 POLE-MOVEMENT IN OSCILLATORS AND ENERGY
BALANCE PRINCIPLE
Pole-movement
in oscillators have been reinvestigated from the perspective of oscillator
nonlinearity, harmonic distortion and soft-self and hard-self excitation.
Quasi-linearization technique and energy balance technique have been used to
evaluate the extent of back and forth pole-movement around the imaginary axis
of the complex frequency plane with reference to a Wien Bridge Oscillator,
22.20 kHz and 6.0% distortion. Experimental results have been presented in
support of theory. A modified Barkhausen Criterion has been proposed for the
nonlinear and non-steady situation of an oscillator demonstrating the transient
behavior during the growth of oscillation.
09:00 C01.4 NEW OBSERVATIONS ON BIAS CURRENT VARIATION
OF OP AMP OSCILLATORS
A
new phenomenon called Bias Current Hump in an injection locked op amp
oscillator. This phenomenon has been used to design a tracking demodulator that
does not require a phase locked nor does it require a discriminator for the
demodulation of an FM signal.This paper reports the result that shows that
there are situations where the bias point dos not remain invariant. It can be
varied both in time and frequency in a controlled manner. This has led us to
develop a tracking demodulator with extremely low distortion. Experimental
results have been presented in support of the theoretical conjecture.
09:20 Tea/Coffee Break
09:40 C01.5 IQ OSCILLATORS: TRACKING AM AND FM
DEMODULATORS
The
behaviour of a quadrature oscillator when subjected to a synchronizing signal
has been analysed and experimentally studied in depth. A non linear theory of
the quadrature oscillator has been presented It has led to the development of a
single shot tracking FM discriminator with excellent interference rejection
capability. It can also be used as a phase locked demodulator exploiting
tracking capability. The signal recovered from the AM-FM signal has a better
signal-to-interference-ratio.
10:00 C01.6 GAIN SENSITIVITIES OF A MICROWAVE
AMPLIFIER WITH RESPECT TO THE MICROSTRIP PARAMETERS
S. Demirel, F. Gunes, Yýldýz Technical University, Istanbul, TURKEY
This
paper presents a method for the sensitivity analysis of the gain with respect
to the width and length of a microstrip line used in any position of the input
/or output matching circuit of a microwave amplifier. The method is applied to
a low-noise amplifier and the resultant typical sensitivity variations are also
given. This work shows which microstrip lines are sensitive with respect
width/or length changes, therefore extra care should be taken for them during
the practical realization stage.
10:20 End of the Session
D01 – RFID Technology and Applications
Session Chair: Smail Tedjini
Session D01
Type Oral Presentation
Schedule Monday, August 15, 08:00-10:40
Room Dolmabahçe B
08:00 D01.1 IMPLANTED RFID TAG FOR PASSIVE VASCULAR
MONITORING
C. Occhiuzzi, G. Contri, G. Marrocco, University of Roma Tor Vergata, Roma, Italy
Starting
from the physical evidence that passive UHF-RFID tags may be used as
self-sensing devices to detect the state of the tagged object, this
contribution address the monitoring of human vascular system by means of
augmented Stents. It is shown through simulations and experimentations how
transforming a mechanical implant, used to recover a stenosis, into a sensor
and communication device embedding RFID chips for the remote detection of the
quality of the vein itself and to prevent restenosis pathology.
08:20 D01.2 COMPARISON OF EXTENDED AND UNSCENTED
KALMAN FILTER FOR LOCALIZATION OF PASSIVE UHF RFID LABELS
Due
to the increased use of Radio Frequency Identification (RFID) in different
fields of application it is reasonable to explore the benefit that can be
obtained by the simultaneous localization of RFID tags. This paper describes
the localization of a passive UHF RFID tag via Extended Kalman Filter (EKF) and
Unscented Kalman Filter (UKF) using the Received Signal Strength Indicator
(RSSI) values. Simulation results based on measurements show that UKF achieves
higher localization accuracies than EKF. When using four antennae for the
localization the error of UKF is about 28cm and 75cm for EKF.
08:40 D01.3 SENSITIVITY ANALYSIS FOR WIRELESS
DIELECTRIC REFLECTOMETRY WITH MODULATED SCATTERERS
Modulated
scatterer systems are increasingly considered for remore sensing applications.
This paper is focused on cases where the sensing mechanism is expected to
result from the change of the probe impedance with the surrounding refractive
index. An analytical-based approach allows to obtain the modulated probe
response sensitivity to the refractive index. Inspired from RCS-based antenna
impedance measurement techniques, the ternary modulation scheme is shown to
remove specific difficulties inherent to wireless reflectometry, such as
misalignment between the probe and reader antennas. Center-loaded dipoles and
meander-line antennas are considered as test cases.
09:00 D01.4 INDOOR LOCALISATION FOR COMPLEX BUILDING
DESIGNS USING PASSIVE RFID TECHNOLOGY
F. M. Khan, K. Menzel, National University of Ireland, University College Cork (UCC), Cork, Ireland
Radio
Frequency Identification (RFID) is a technology that has proved its importance
over the years with ever increasing research and advancements in place.
Applications of RFID are exploited in many different industries ranging from
Supply Chain and Retail to applications in Medicine and Military. This paper
presents an algorithmic technique for indoor localization using Passive RFID
Technology. A mathematical explanation of the algorithm is explained with
simulated results of positioning accuracy. Hardware design and implementation
methodology is discussed afterwards. The application usage of this technique
can be in areas of medicine and the retail sector.
09:20 Tea/Coffee Break
09:40 D01.5 PAPER-BASED, INKJET-PRINTED,
TEXT-MEANDERED UHF RESONANT ANTENNAS FOR RFID APPLICATIONS
In
this paper different antennas manufacturing and designing techniques are
combined with the aim of building useful radiators resonating in the UHF band.
The meander lines techniques is exploited in this work with the exception of
letters as meander elements. The technologically advanced and already well
established silver inkjet printing technique is used for antenna realization.
An unusual paper-based substrate is chosen, according with the concepts to
lower costs, simplify fabrication procedures and advance usability, towards the
realization of antenna for RFID applications. All design phases are discussed
and a complete test of the proposed antennas is performed.
10:00 D01.6 METALLIC LETTER IDENTIFICATION BASED ON
RADAR APPROACH
A. Vena, T. Singh, S. Tedjini, E. Perret, Grenoble-Inp LCIS, Valence, France
A
new concept of letter identification by use of RF wave is presented in this
paper. Since letters have various shapes, their Electromagnetic signature can
be identified independently. To measure the electromagnetic signature of each
letter, a wideband measurement set-up has been used with a frequency span until
10 GHz. It is based on a bi-static radar system with a pulse generator as
source, compatible with UWB regulations, and a real time sampling oscilloscope
as receiver. The greatest interest of using metallic letters is based on
combining the visual identification, with the remote Electro Magnetic identification.
10:20 D01.7 A NOVEL XTEA BASED AUTHENTICATION PROTOCOL
FOR RFID SYSTEMS
G. N. Khan, F. Yuan, J. Yu, Ryerson University, Toronto, ON, Canada
RFID
technology has been widely used in logistic, automation and authentication
applications. It still has many potential issues of privacy and security. We
present a novel XTEA encryption based authentication protocol. Analysis of its
security and privacy is performed using FPGA based prototyping. Different
attack models are implemented, and the results show that the protocol is robust
and safe against major attacks. The protocol is analyzed and compared with
other two similar protocols, Analysis of its performance as compared to related
works show its advantages in code size, clock cycle, communication cost and
scalability.
10:40 End of the Session
E01 – EMC Interactions in Complex Systems
Session Chairs: Flavio Canavero, Christopher Holloway
Session E01
Type Oral Presentation
Schedule Monday, August 15, 08:00-10:40
Room Galata
08:00 E01.1 DEALING WITH COMPLEXITY IN EMC MODELLING
C. Christopoulos, University of Nottingham, Nottingham, United Kingdom
The
paper addresses features of EMC making it a challenging modeling application.
These include the very broadband nature of the interactions encompassing
regions of non-linearity and uncertain parameter values; the inherent
uncertainties in geometrical configurations and dimensions of the multitude of
components; and the ubiquitous presence of multi-scale features. The challenge
is to address complexity without resorting to extremely lengthy computations
which require enormous computational resources and tedious, time consuming
problem definition and input data preparation. The emphasis of this paper is on
the embedding of macromodels to describe complex materials and the treatment of
uncertainties.
08:20 E01.2 MODELING COMPLEX SYSTEMS FOR EMC
APPLICATIONS BY CONSIDERING UNCERTAINTIES
The
objective of this work is to present a new approach to the random modeling of
complex systems in ElectroMagnetic Compatibility (EMC). This contribution aims
to compute high orders statistics and study the impact of parameter
uncertainties on various EMC topics including transmission lines, radiation and
immunity problems. The agreement between results from the Stochastic
Collocation (SC) method and Monte-Carlo (MC) simulations guarantee the SC
accuracy and robustness. The combination of SC with computations from
analytical and tridimensional numerical models (Finite Difference in Time Domain)
underlines its advantages (efficiency, non-intrusive integration).
08:40 E01.3 ON THE USE OF THE MONTE CARLO METHOD FOR
ELECTROMAGNETIC FIELD SIMULATION
A. Kreth, O. Doering, E. Genender, H. Garbe, Leibniz Universitaet Hannover, Hannover, Germany
The
knowledge of electromagnetic interferences plays a significant role in todays
research and development. However, the actual realization of large systems may
vary or even be unknown. Hence, the electromagnetic field of the system has to
be estimated statistically. Therefore this work describes how a statistical
field simulation of the electromagnetic field of the system can be accomplished
by modeling the system with subsystems and varying the parameters of these
subsystems.
09:00 E01.4 STATISTICAL ESTIMATION OF ANTENNA GAIN
FROM MEASUREMENTS CARRIED OUT IN A MODE-STIRRED REVERBERATION CHAMBER
C. Lemoine, E. Amador, P. Besnier, J. Sol, J.-M. Floc'h, IETR / INSA de Rennes, Rennes, France; A. Laisne, DGA - TA, Balma, France
This
paper proposes for the first time a method for estimating the gain of an
antenna in a mode-stirred reverberation chamber. The method is based on the
estimation of the Ricean K-factor which provides the relative transmitting
power level of the line-of-sight path. Experimental results are compared with
anechoic chamber measurements using a set of different antennas.
09:20 Tea/Coffee Break
09:40 E01.5 MEASUREMENT OF SHIELDING EFFECTIVENESS OF
ELECTRICALLY SMALL ENCLOSURES
In
the following we propose a technique for determining the shielding
effectiveness of an electrically small enclosure with an electrically small
aperture. In particular, we use this technique to explore the shielding
characteristics of a rectangular box used to shield devices. Measurement and
simulation results are presented in order to validate the technique and to show
that, when a source is placed inside the box, different aperture shapes on the
face of the enclosure will produce different internal and external field
patterns, and have different shielding characteristics.
10:00 E01.6 NUMERICAL ELECTROMAGNETIC MODELING OF
CHEMICAL PLANTS FOR THE ASSESSMENT OF RADIO FREQUENCY IGNITION HAZARDS
G. Spadacini, S. A. Pignari, Politecnico di Milano, Milan, Italy
In
this work, electromagnetic simulation of electrically-large chemical plants is
used to investigate RF ignition hazards. The proposed analysis is aimed at
refining results and procedures detailed in the European Standard CLC/TR 50427,
which foresees the use of elemental antennas (loops and half-wave dipoles) for
the estimation, via closed-form approximated formulas, of the RF power induced
by an impinging electromagnetic field.
10:20 E01.7 MODELING OF THE ELECTROMAGNETIC COUPLING
TO ELECTRO-EXPLOSIVE DEVICES
In
this work, we present a general methodology for modeling the coupling of
electromagnetic fields with electro-explosive devices (EEDs). We discuss the
assumptions and the necessary conditions to achieve the maximization of
electromagnetic response of a canonical EED. The product of the EED (E being
the electric field and the duration) is presented as a means for determining
the electromagnetic environment that could lead to its activation from an
external impinging electromagnetic field.
10:40 End of the Session
F01 – State-of-the-Art Developments in Propagation and Remote sensing
Session Chairs: Madhu Chandra, Roger Lang
Session F01
Type Oral Presentation
Schedule Monday, August 15, 08:00-10:40
Room Haliç
08:00 F01.1 RADIOMETRY AND REMOTE SENSING OF THE
ENVIRONMENT
R. H. Lang, George Washington Uniiversity, Washington, Dc, United States
Three
new L band passive satellite missions to measure sea surface salinity and soil
moisture are reviewed. The first is the ESA Soil Moisture Ocean Salinity (SMOS)
satellite. It features the first spaceborne synthetic aperture antenna with
enhanced resolution and multiple incident angle looks. The second is the NASA
Aquarius mission to sense sea surface salinity with a 0.2psu accuracy and an
on-board radar to correct for surface roughnesss. The last is NASAs Soil
Moisture Active Passive (SMAP) mission to measure soil moisture with a 6m mesh
antenna for increased resolution and a radar to enhance its performance.
08:20 F01.2 RF ELECTROMAGNETIC MEASUREMENTS IN A RURAL
ENVIRONMENT
Radioelectrical
power measurements taken in the 20 MHz - 3 GHz frequency band in a typical
rural environment are presented. They show that the spectrum is very clean
outside frequency band allocated to land, aeronautical and maritime
radiocommunication and more particularly in frequency bands allocated to
radio-astronomy, spatial research, remote sensing, radio navigation. They show
that the site environment does not suffer from strong electromagnetic fields
able to create non linearity in the relevant frequency band. Calculated to the
antenna level, electric fields are weak compared to standard limit values legal
in France and in the European Union.
08:40 F01.3 JOINT ANALYSIS OF RADIO FREQUENCY
INTERFERENCE FROM SMOS MEASUREMENTS AND FROM AIRBORNE OBSERVATIONS
M. Aksoy, J. Park, J. T. Johnson, The Ohio State University, Columbus, OH, United States
The
Soil Moisture and Ocean Salinity (SMOS) mission has been providing L-band
brigthness temperatures since November 2009. However, SMOS has been affected by
significant levels of radio frequency interference. Since SMOS has a single
frequency channel and low time resolution, RFI mitigation is a challenging problem
especially for low level RFI. In this paper, possible RFI detection strategies
using SMOS full polarimetric data are discussed by utilizing an airborne
campaign called SMAPVEX08. The results suggest that polarimetry can be used as
an indication of some RFI sources although it may not reflect RFI
characteristics in general.
09:00 F01.4 CHARACTERIZATION OF RADAR TARGETS BASED ON
ULTRA WIDEBAND POLARIMETRIC TRANSIENT SIGNATURES
H.-S. Lui, M. Persson, Chalmers University of Technology, Gothenburg, Sweden
Resonance
based target recognition has been well studied for the last three decades. The
purely target dependent natural resonant frequencies are used as a feature set
for target classification. Such technique may fail if the targets of interest
have similar or almost the same resonant frequencies. In this paper, the idea
of using the polarimetric features at the resonant frequencies is investigated
and demonstrated via numerical examples.
09:20 Tea/Coffee Break
09:40 F01.5 GLOBAL MAPPING OF RAINFALL FROM TRMM RADAR
LINKING GROUND BASED RADARS AND IN-SITU OBSERVATIONS
Tropical
Rainfall measuring Mission Precipitation Radar is known to be the first
spaceborne observation platform for mapping precipitation over the tropics.
TRMM measured rainfall is important in order to study the precipitation
distribution. Ground validation is a critical important component in TRMM
system. However, the ground sensing systems have different sampling and
observation characteristics from TRMM. In this paper a novel hybrid Neural
Network model is presented to train ground radars for rainfall estimation using
rain gauge data and subsequently using the trained ground radar rainfall
estimation to train TRMM PR based Neural networks, to create Global maps of
precipitation.
10:00 F01.6 COMPACT SUB MILLIMETER WAVELENGTH
HETERODYNE RADIOMETER FOR ARRAYS
We
present a very compact frontend radiometer at 300-360 GHz, which requires a
local oscillator power at 60 GHz. A single receiver element is developed to fit
n x m element 2D focal plane array, where n and m > 2. This element array is
packaged in a block with a cuboid outline. The attractiveness of this
configuration is that the input/output of the receiver are contained within the
footprint of the antenna, therefore a full two-dimensional array is possible.
10:20 F01.7 REFLECTION ON CURVED SURFACES IN A 2.5D
RAY-TRACING METHOD FOR ELECTROMAGNETIC WAVES EXPOSURE PREDICTION IN URBAN AREAS
N. Noe, CSTB, Nantes, France; F. Gaudaire, CSTB, Grenoble, France
Asymptotic
methods are commonly used to predict exposure to electromagnetic waves in large
environments such as urban areas. Specifically 2D beam-tracing is a very
efficient solution in case of GIS 2.5D environments. Nevertheless taking into
account reflection on curved vertical walls or curved ground in such methods is
not straightforward. Indeed curved surfaces are mostly described as meshes and
lead to artificial shadowing and inaccurate electric field estimation. We
explain here how to avoid such problems without modifying existing geometry by
using normal interpolation in a generalized beam-tracing technique, and present
results for some real cases.
10:40 End of the Session
G01 – Open Session and Latest Results I
Session Chairs: Paul Cannon, Michael Rietveld
Session G01
Type Oral Presentation
Schedule Monday, August 15, 08:00-10:40
Room Topkapi A
08:00 G01.1 HOW IS THE IONOSPHERE DRIVEN BY THE
MAGNETOSPHERE?
In
the ionospheric community, the electric field is often considered the driver of
the ionospheric motion. We demonstrates from theoretical points of view that
the electric field cannot be the driver of the motion. Instead, the electric
field is a result, not the cause, of the motion. The causal relationship can be
clearly understood in particular in dynamic processes and in heating processes.
We call for a review and correction of the misused concept of electric field
being a driver of motion and in particular the incorrect concept of penetration
electric field.
08:20 G01.2 MULTI-INSTRUMENT OBSERVATIONS OF AN MSTID
OVER ARECIBO OBSERVATORY
The
Penn State All-Sky Imager (PSASI) at Arecibo Observatory provides planar
horizontal context to the vertical ionospheric profiles obtained by the
Incoherent Scatter Radar (ISR). Electric field measurements from the
Communication/Navigation Outage Forecast System (C/NOFS) satellite are mapped
down geomagnetic field lines to the height of the airglow layer, allowing multi-instrument
studies of field-aligned irregularities with radar, imager, and satellite. A
Medium-Scale Traveling Ionospheric Disturbance (MSTID) was observed during such
a conjunction near the December solstice of 2009.
08:40 G01.3 EQUATORIAL COUNTER ELECTROJETS:- AN
INVESTIGATION USING THE GROUND BASED OPTICAL AND RADIO PROBING TECHNIQUES.
This
study presents the behavior of daytime zonal wind and OH temperature at upper
mesospheric altitudes during afternoon Equatorial Counter Electrojet (CEJ)
events over a dip equatorial station, Trivandrum (8.5oN, 76.5oE, 0.5oN dip
lat.) in India. The measurements were carried out using a unique
Multiwavelength Dayglow Photometer (MWDPM), Meteor Wind Radar and Proton
Precession Magnetometers. It is observed that during the CEJ events: (i) zonal
wind at 98 km exhibits an eastward acceleration and (ii) the mesopause
undergoes a cooling, which in turn is proportional to the strength of CEJ. The
paper discusses these results in detail.
09:00 G01.4 LONG-DISTANCE PROPAGATION EFFECTS IN THE
HF SIGNALS FROM DIFFERENT HEATING FACILITIES OBSERVED WITH USING PASSIVE
DOPPLER SOUNDING EQUIPMENT AT IRKUTSK
We
present the first observation results of long-distance propagation effects of
short radio waves at pump frequency, observed by passive Doppler sounding
equipment at Irkutsk during heating facilities operation. We demonstrate two
effects: dependence of the received signal amplitude on the propagation path
during power-stepping mode and difference between experimental observations and
propagation expectations according to our model.
09:20 Tea/Coffee Break
09:40 G01.5 VARIATIONAL METHODS IN IONOSPHERIC RAY
TRACING
C. J. Coleman, The University of Adelaide, Adelaide, Australia
Ray
tracing is an important tool in the study of radio wave propagation. In
particular, numerical solutions to the Haselgrove ray equations have proven to
be one of the most useful techniques for ray tracing in the ionosphere.
Haselgrove equations are differential equations that are derived from Fermats
principle which also provides a variational equation for ray tracing. The
present paper will discuss the problems of directly solving Fermats principle and
describe some recent work that has led to a successful variational approach to
ionospheric ray tracing with magneto-ionic effects included.
10:00 G01.6 USE OF A DRM MODULATION TO STUDY THE
IONOSPHERE
The
aim of this article is to introduce a technology of investigation of the
ionosphere based on reception of a numerical broadcasting fixed link at 6.085
MHz using the DRM (Digital Radio Mondiale) modulation properties as an
opportunistic ionospheric sounder. The analysis used tools are Dream and
SpectrumLab software. Observations are accomplished at the same time in narrow
band (2Hz) and in wide band (10 kHz). They are presented by dopplergram.
Different ionospheric characteristic events are observed in narrow band
(typical figures, scattering, absorption, gravity waves) and in large band
(selective fading, scattering, absorption). Different typical examples are
presented.
10:20 G01.7 THE EFFECT OF IONOSPHERIC SCINTILLATION ON
PHASE GRADIENT AUTOFOCUS PROCESSING OF SYNTHETIC APERTURE RADAR
This
paper considers the effects of scintillation (variations in amplitude and
phase) on a narrow band synthetic aperture radar (SAR) that utilizes the
phase-gradient autofocus (PGA) method that attempts to compensate for the
effects of phase errors across the synthetic aperture. The multiple phase
screen (MPS) technique is used to model the effects of amplitude and phase
scintillation for a spotlight-mode SAR operating in the equatorial region.
Examples are presented of the performance of SAR/PGA for values of the
decorrelation distance and scintillation index that represent natural
ionospheric scintillation at UHF.
10:40 End of the Session
H01 – Nonlinear Waves and Turbulence in Plasmas
Session Chairs: Meers Oppenheim, Hideyuki Usui, David Shklyar
Session H01
Type Oral Presentation
Schedule Monday, August 15, 08:00-10:40
Room Topkapi B
08:00 H01.1 SAID-RELATED NONLINEAR WAVE EFFECTS
E. Mishin, Air Force Research Laboratory, Space vehicles Directorate, Hanscom AFB, MA, United States
We
present recent observations from the Cluster spacecraft that have shown that
excitation of lower hybrid/fast magnetosonic waves plays the fundamental role
in SAID formation. The SAID channel is a turbulent plasmaspheric boundary layer
formed via a short circuit of substorm-injected plasma jets. Nonlinear
wave-particle interactions provide fast magnetic diffusion at the leading front
and define the circuit's anomalous resistivity, similar to the well-documented
plasmoid-magnetic barrier problem. Mainly gradient-drift and current-driven
instabilities operate near the outer boundary of the SAID channel, while
anisotropic ion-driven processes dominate near the inner boundary.
08:20 H01.2 SOLITON MODEL FOR BROADBAND ELECTROSTATIC
NOISE
Generation
of broadband electrostatic noise (BEN) in the plasma sheet boundary layer
(PSBL) by electron-acoustic solitons and double layers is proposed. PSBL is
treated as multi-component magnetized plasma consisting of background
electrons, counter-streaming electron beams and ions. Theoretical model is
based on multi-fluid and Poisson equations and uses Sagdeev pseudo-potential
technique. For PSBL plasma parameters, during BEN event observed by Cluster on
22 September 2004, the model predicts solitons/double layer with electric field
(0.01-30) mV/m. The proposed model can be good candidate for explaining the
generation of BEN in the PSBL.
08:40 H01.3 ELECTRON ACOUSTIC SOLITONS IN THE PRESENCE
OF AN ELECTRON BEAM AND SUPERTHERMAL ELECTRONS
Existence
of arbitrary amplitude electron acoustic solitons is studied in an unmagnetized
plasma having cold electrons and ions, superthermal hot electrons and an
electron beam. Using Sagdeev pseudo potential method, theoretical analysis is
carried out by assuming superthermal hot electrons having kappa distribution.
The results show that inclusion of beam alters the minimum value of spectral
index and Mach number for which electron-acoustic solitons can exist. For the
auroral region parameters, the maximum electric field amplitudes and soliton
widths are found in the range ~ (100-400) mV/m and ~ (314-515) m, respectively.
09:00 H01.4 VLF AND HF PLASMA WAVES ASSOCIATED WITH
SPREAD-F PLASMA DEPLETIONS OBSERVED ON THE C/NOFS SATELLITE
The
C/NOFS spacecraft frequently encounters structured plasma depletions associated
with equatorial spread-F along its trajectory that varies between 401 km
perigee and 867 km apogee in the low latitude ionosphere. We report two classes
of plasma waves detected with the Vector Electric Field Investigation (VEFI) in
the VLF and HF frequency regimes that appear when the plasma frequency is less
than the electron gyro frequency, as is common in spread-F depletions where the
plasma number density typically decreases below 104/cm3.
09:20 Tea/Coffee Break
09:40 H01.5 3D SIMULATIONS OF FARLEY-BUNEMAN
TURBULENCE DEMONSTRATES ANOMALOUS ELECTRON HEATING
M. M. Oppenheim, Y. S. Dimant, Boston University, Boston, MA, United States
Field
aligned currents flow from the magnetosphere to the E-region ionosphere where
they drive the intense currents of the auroral electrojet. These currents often
cause Farley-Buneman (FB) instabilities to develop and become turbulent. The
resulting electron density irregularities affect ionospheric conductivity,
temperatures, and radio wave propagation. We will discuss 3-D PIC simulations
showing intense anomalous electron heating due to turbulence, a phenomena
clearly observed by radars. These simulations also show the saturated amplitude
of the waves; coupling between modes; the evolution from by shorter to longer
wavelengths; and dominant phase velocities at close to the acoustic speed.
10:00 H01.6 NONLINEAR, INTERMITTENT E-REGION
IRREGULARITIES: WHAT DO WE REALLY KNOW?
A. M. Hamza, University of New Brunswick, Fredericton, NB, Canada
One
of the most fundamental challenges of ionospheric physics is to explain why the
largest amplitude structures tend to move at phase speeds that do not exceed on
average the linear theory threshold? To provide a solution one has to rely on
nonlinear theory in order to study the development and evolution of nonlinear
ionospheric structures. We propose to study the development and evolution of
nonlinear, large-amplitude, intermittent E-region plasma structures. We will
set up the analytical model, and compare the predictions of the model to
ionospheric E-region experimental observations.
10:20 H01.7 TOWARDS A POSSIBLE RESOLUTION OF THE
150-KM RIDDLE
High-resolution
incoherent scatter radar Faraday rotation and digital ionosonde data from
Jicamarca indicating the presence of km-scale electron density variations in
the equatorial upper E-region will be presented and discussed in relation to
the generation mechanisms of meter-scale field-aligned density fluctuations known
as 150-km irregularities. The km-scale density variations are likely to be a
consequence of gravity-wave imposed dynamics of the geomagnetically constrained
plasma in the region. This conjecture is supported by the gravity-wave-period
oscillations and downward phase progression of intensity variations of
meter-scale waves observed in the region.
10:40 End of the Session
J01 – Low Frequency Radio Astronomy I – (LOFAR, LWA, MWA, GMRT, any other)
Session Chairs: Colin Lonsdale, Mike Garrett
Session J01
Type Oral Presentation
Schedule Monday, August 15, 08:00-10:40
Room Marmara
08:00 J01.1 LONG WAVELENGTH RADIO SCIENCE:
INSPIRATIONS FROM ASTRONOMY
R. Subrahmanyan, Raman Research Institute, Bangalore, India
The
last decade has been witness to precision cosmology via measurements of the
cosmic microwave background. More recently, the window of exploration and
discovery in radio astronomy has moved to long wavelengths where solutions to
frontier problems in many areas of astrophysics have vital clues. A key science
is the detection of trace spatial and spectral signatures in the sky brightness
at long wavelengths arising from events at the cosmic dawn that are associated
with the formation of first stars and galaxies and their impact on the gas. I
review astrophysics that inspires innovation in long wavelength radio science.
08:20 J01.2 CALIBRATION CHALLENGES FOR LOW FREQUENCY
RADIO ASTRONOMY
W. D. Cotton, National Radio Astronomy Observatory, Charlottesville, VA, United Statesj
A
major challenge for all high resolution low frequency radio astronomy is
measuring and removing the effects of the ionosphere. The isoplanatic patch
size for frequencies below a few hundred MHz is generally much smaller than the
field of view. In addition, aperture arrays have beams on the sky which vary
dramatically with observing geometry. These beams require careful calibration
to be stable and known in order to allow imaging. Various approaches to these
problems will be discussed.
08:40 J01.3 SITE REQUIREMENTS AND CHALLENGES FOR LOW
FREQUENCY RADIO OBSERVATIONS
R. P. Millenaar, SPDO, Manchester, United Kingdom
Observing
the early universe, in particular detecting the signature of the EOR is an
important science target for the SKA and other new radio telescopes. These high
redshift observations require excellent performance at low frequencies, as low
as 50 MHz. Observations will be carried out in a crowded part of the radio
spectrum, even at the very radio-quiet sites that are considered. Propagation
of RFI at these frequencies can be highly variable and the influence of the
ionosphere on propagation is felt strongly in this frequency range. An overview
of issues and challenges is presented.
09:00 J01.4 WIDEBAND LOW FREQUENCY ANTENNAS FOR RADIO
ASTRONOMY ARRAYS
Antennas
in the frequency range 10 to 300 MHz are being designed with all-sky coverage,
a low response at the horizon to minimize interference from terrestrial
sources, negligible ground loss and a good low noise match to the low noise
amplifier. Other features include low cost, dual polarization and good performance
over more than an octave bandwidth. Extending the antenna performance over a
wider frequency range and accurate calibration are remaining challenges.
Modeling of the antenna and its associated low noise amplifier shows promise as
a method of improving calibration accuracy.
09:20 Tea/Coffee Break
09:40 J01.5 LOFAR: A POWERFUL AND FLEXIBLE OBSERVATORY
FOR PULSARS AND FAST TRANSIENTS
LOFAR
is a sparse aperture array radio telescope that can observe from 10-240MHz -
i.e. the lowest radio frequencies observable from Earth. Construction of the
LOFAR core is all but complete and regular observations of pulsars and other
rapidly varying radio sources have begun. With it's huge field-of-view,
flexible multi-beaming capabilities, and large collecting area, LOFAR promises
to revolutionize observations of transient radio phenomena with durations of
nanoseconds to years. Here we highlight a few of the most recent LOFAR pulsar
observations, which demonstrate that the system is already producing
science-quality data.
10:00 J01.6 THE LOFAR MAGNETISM KEY SCIENCE PROJECT
The
low frequencies observed by the LOFAR telescope make it a unique probe of weak
magnetic fields in the Universe. I will describe the LOFAR Magnetism Key
Science Project (MKSP) and give an overview of some of the key science drivers
which motivate this KSP. I will describe the observational techniques being
utilised to recover polarization and magnetism information with LOFAR and show
some of the early results from the KSP commissioning.
10:20 J01.7 DETECTING THE EOR WITH LOFAR: STEPS ALONG
THE ROAD
In
December 2010 we started observations with a partially completed LOFAR, to
prepare ourselves for the calibration and processing of deep (hundreds of
hours) integrations in a number of Galactic halo windows. These observations
are aimed at detecting the redshifted 21cm signals from the Epoch of
Reionization using the LOFAR HBA antennas (115-190 MHz, z=11.4 6.3). Two fields
have been observed for about a dozen nights in the Spring of 2011. The data
have been mostly processed on a dedicated EoR-project cluster. Some results and
first conclusions from the analysis of these data is presented.
10:40 End of the Session
Session Chairs: Lluis Mir, P. Thomas Vernier
Session K01
Type Oral Presentation
Schedule Monday, August 15, 08:00-10:40
Room Loft
08:00 K01.1 MODELING ELECTROMAGNETIC FIELD EFFECTS IN
A BIOCHEMICAL REACTION: UNDERSTANDING REACTIVITY INHIBITION DUE TO THE MAGNETIC
FIELD
In
this work we have used MD simulations combined with quantum mechanical
calculations to model the spin state relaxation of a common biochemical
reaction utilized for an experimental study on magnetic field effects. Data
clearly show that a 0.2T static magnetic field strongly inhibits the spin
relaxation process avoiding the 1 triplet to singlet state transitions. Such a
result sheds light on the atomistic mechanism of the magnetic field effects and
opens the way to further investigations possibly leading to a detailed
description of the complex biochemical-biophysical processes involved in the
interaction between EM-fields and biomolecular systems.
08:20 K01.2 THE ROLE OF WATER NEAR CHARGED INTERFACES:
MOLECULAR DYNAMICS SIMULATIONS OF BIOLOGICAL MACROMOLECULES IN PRESENCE OF HIGH
INTENSE ELECTRIC FIELDS
Because
of its central role in basically all aspects of science, water is certainly one
of the most extensively investigated substances. Moreover, the characterization
of liquids and solutions under the effect of external electric fields is a long
standing and challenging field of investigation for both theoretical and
experimental approaches. In this work the behavior of water near charged
interfaces has been evaluated considering two different cases: an ion in
aqueous solution and a macromolecule of DNA. The methodology used is based on
atomistic simulations, specifically adapted to account for the presence of
exogenous electric fields.
08:40 K01.3 STRUCTURE AND ELECTROPORATION OF LIPID
BILAYERS: A MOLECULAR DYNAMICS STUDY
Pore
formation in lipid bilayers subjected to a transverse electric field is studied
by means of Molecular Dynamics simulations of
1,2-dipalmitoyl-sn-glycero-3-phosphatidylcholine (DOPC). The physical
characteristics of the lipid membrane are crucial to understand the
electroporation conditions. For example, addition of cholesterol (Chol) causes
a substantial increment of membrane cohesion that results in an increase of the
minimum electric field needed for membrane permeabilization. Instead, dimethyl
sulfoxide (DMSO) is known to produce an opposite effect on membrane properties
by increasing its fluidity and disorder that may open the possibility to
facilitate the membrane electroporation process.
09:00 K01.4 NANOSECOND (GIGAHERTZ) AND MICROSECOND
(MEGAHERTZ) PULSED ELECTRIC FIELD INTERACTIONS WITH CELL MEMBRANES
P. T. Vernier, University of Southern California, Los Angeles, CA, United States
High-intensity
nanosecond pulsed electric fields permeabilize cell membranes, restructure
phospholipid bilayers, cause intracellular calcium release, depolarize
mitochondrial membranes, and induce apoptosis. Molecular simulations reveal the
mechanism for the electric field-driven reorganization of phospholipid head
groups and water molecules that results in the formation of membrane-spanning
water bridges and conductive pores. Progress has been made in taking nanosecond
electric pulses to the clinic for the treatment of skin cancers and other
lesions, but a deeper understanding of the underlying biophysical phenomena
will facilitate the application of this technology in cancer therapeutics
through non-thermal, minimally scarring tumor ablation.
09:20 Tea/Coffee Break
09:40 K01.5 EXPOSURE OF CELLS IN SUSPENSION USING
NANOSECOND DURATION ELECTRIC PULSES - DETECTION OF PERMEABILISATION BY CLONING
EFFICIENCY TESTS: RESULTS AND ARTIFACTS.
A. Silve, L. M. Mir, CNRS UMR 8203, Villejuif, France
Intense
(several MV/m) nanosecond duration electric pulses can induce damages on cells
external membrane which can be detected by direct cell killing or by the uptake
of non permeant molecules. We detail here the methodology to carry out those
experiments, drawing the attention to exposure artifacts that demonstrate the
importance of the implementation of a metrology specific to the ultrashort
pulses.
10:00 K01.6 AN EXPERIMENTAL INVESTIGATION OF
TEMPERATURE CHANGES DURING ELECTROPORATION
P. A. Garcia, R. E. Neal II, M. B. Sano, R. V. Davalos, Virginia Tech, Blacksburg, VA, United States
Electroporation
uses short, pulsed electric fields to induce a cellular transmembrane potential
that results in increased cellular permeability. When performed irreversibly,
it results in cell death while leaving the extracellular matrix and other
sensitive structures intact. These electric fields result in thermal effects to
the affected tissues due to resistive heating. We measure this heating extent
in an ex-vivo canine brain by recording temperature changes in real time.
Temperatures were measured at three locations near the electrodes. Thermal
damage was evaluated using the Arrhenius equation. This study experimentally
shows that typical electroporation protocols result in negligible thermal
damage.
10:20 K01.7 ELECTROCHEMOTHERAPY
L. M. Mir, CNRS, Villejuif, France
Electrochemotherapy
is a new antitumor strategy based on the delivery of short (100 microseconds)
electric pulses and non-permeant anticancer drugs such as bleomycin. The
electric pulses, which must cover the whole of the tumor volume, make permeable
the cell membrane and allow the unrestricted penetration of the drug.
Electrochemotherapy is a safe, very efficient and cost-effective treatment
which is spreading in the EU for the treatment of cutaneous and subcutaneous
lesions of any histological origin. The bases, indications and present clinical
trials, targeting internal and deep-seated tumors, will be reported.
10:40 End of the Session
Session Chair: Karl Langenberg
Session BT
Type Oral Presentation
Schedule Monday, August 15, 09:40-10:40
Room Anadolu Auditorium
09:40 BT.1 PASSIVE AND ACTIVE METAMATERIAL CONSTRUCTS
AND THEIR IMPACT ON ELECTRICALLY SMALL RADIATING AND SCATTERING SYSTEMS
R. W. Ziolkowski, University of Arizona, Tucson, AZ, United States
In
the last decade, the metamaterials field has enabled numerous exciting
electromagnetic advances. Exotic physics properties have led to the engineering
of metamaterials and metamaterial-inspired structures for a variety of
applications, including the miniaturization of resonators and their use for
improving the performance characteristics of electrically small antennas and
optical scatterers. Active metamaterial constructs have been introduced to
increase the bandwidths at low frequencies and to overcome losses at high
frequencies. The theoretical designs of many of these highly subwavelength
systems and their simulated performance characteristics have been confirmed
experimentally. These concurrences between theory and experiment will be
highlighted.
10:40 End of the Session
Session Chair: Madhu Chandra
Session GL1
Type Oral Presentation
Schedule Monday, August 15, 11:00-12:00
Room Anadolu Auditorium
11:00 GL1.1 SMOS: FROM REQUIREMENTS TO RESULTS VIA RADIO SCIENCE
Y. Kerr, CESBIO, Toulouse, France
It
is well established that data on soil moisture and sea surface salinity are
required to improve meteorological and climatic predictions. These two
quantities are not yet available globally or with adequate temporal sampling.
It is within this framework that the European Space Agency (ESA) selected the
Soil Moisture and Ocean Salinity (SMOS) mission as its second Earth Explorer
Opportunity Mission. SMOS is a very novel instrument and is based on a passive
microwave interferometer (as in radioastronomy) operating at L band (1.4 GHz)
Since the 2nd of November, 2009, date of its launch, SMOS observations have
provided an unprecedented maximum spatial resolution of 50 km at L-band over
land, together with multi-angular fully polarized brightness temperatures over
the globe. SMOS has a revisit time of less than 3 days which permits the
retrieval of soil moisture and ocean salinity data in accordance to the
mission’s science objectives. Now, after the commissioning phase and more than
one year of operations, SMOS is entering the phase in which the retrieval
algorithms stabilises and new applications can be derived from the SMOS data
over land, all leading logically to a better management of water resources.
Currently, the main applications tackled are flood monitoring and risks
forecasting, drought monitoring and potential forecasting with associated fire
risks. Using some specific sites, we are also considering applications in terms
of water management (i.e., irrigation monitoring) as well as ways to
disaggregate SMOS data into finer scales. However, the SMOS data is hampered by
radio-frequency interferences (RFI), and the whole team is working to deal with
this issue. During the presentation, an update of the SMOS mission and results
will be presented together with new results and a glimpse of those potential
applications. We will also depict the RFI issue as well as other similar
missions to be launched (Aquarius and SMAP).
12:00 End of the Session
A02 – Fractals - Design and Measurement
Session Chair: William Davis
Session A02
Type Oral Presentation
Schedule Monday, August 15, 13:40-15:40
Room Dolmabahçe C
13:40 A02.1 HILBERT CURVE FRACTAL ANTENNA FOR WLAN APPLICATION
R. M. Haridas, J. Chandwani, P. Musale, S. V. Khobragade, Dr. Babasaheb Ambedkar Technolgogical University Lonere, Raigad, Mangaon, India; V. R. Anitha, Sree Vidyaniketan College of Engineering Tirupati, Tirupati, India
In
this paper we propose the fractal antenna using Hilbert Curve. The purpose of
this paper is to design the Hilbert curve fractal antenna WLAN application at
5GHz frequency. Theoretical performance of this antenna has been calculated and
presented in the paper. Simulation results show that the antenna have multiband
resonate behavior. The results have shown that this antenna has acceptable
performance that is VSWR ≤ 2 and return loss ≤ -10dB. This feature
provides antenna designer with more degree of freedom and makes the proposed
antenna suitable for use in modern multifunction communication system.
14:00 A02.2 STUDY OF SIERPINSKI CARPET FRACTAL ANTENNA
In
the today‟s world of communication, low cost of fabrication and low
profile features of microstrip antennas, attract many researchers to
investigate the performance of this antenna . Carpet antenna is new member in
the antenna family. They have peculiar properties that make them suitable for
applications where wideband, multiband and frequency independence are important
parameters of the overall performance. Fractal technology allowed us to design
miniature antennas and integrate multiple telecommunication services into a
single device. The design of carpet antenna with multiple bands for the
services viz. WLAN, satellite and Laser communications is studied in this
paper.
14:20 A02.3 TRIPLE BAND FRACTAL UWB ANTENNA USING U
AND C SLOT FOR WIRELESS COMMUNICATION
Fractal
UWB antenna with triple band for wireless communication system is designed. U
slot is inserted in the original patch to generate second resonant at 5.0
(GHz). Another C-slot is inserted to generate 5.7 (GHz) third band. This system
may include various application such as GPS, wireless local-area network (WLAN)
and Hiper LAN. Four iterations of fractal wide band antenna are arranged and
examined. With this structure the designed antenna has operating frequency of 1.8-GHz,5.0-GHz
and 5.7GHz with acceptable bandwidth of 80%,30%,3% and S11<-10dB
(VSWR<2).
14:40 A02.4 PROXIMITY-COUPLED NOVEL DESIGN OF FRACTAL
TREE ANTENNA MINIATURIZATION
In
this paper, for more antenna miniaturization, we present Novel fractal tree
geometry that allows decrease in resonance frequency without occupying more
space. For improving inherently narrow bandwidth of Fractal antenna
Proximity-coupled feed is implemented. Proposed Fractal Tree antenna is
designed for 2.4 GHz, 3.6 GHz. The -10 dB return loss bandwidth could reach
about 9.5% for 2.4 GHz band and 31.5% for 3.6 GHz band, which meet required
bandwidth specification of 2.4/3.6 GHz WLAN standard. Radiation pattern of
fractal antenna is nearly omnidirectional in azimuth plane throughout operating
frequency.
15:00 A02.5 STUDY OF SIERPINSKI TRIANGLE GASKET BY USING STRIP FEEDING
A. Lale, B. Khiste, G. Burshe, S. Khobragade, Dr. Babasaheb Ambedkar Technological University,Lonere, Maharashtra, India; V. R. Anitha, Sree Vidyaniketan College of Engineering Tirupati, Tirupati, India
A
Sierpinski triangle gasket antenna are developed to achieve a suitable
bandwidth for wireless communication This triangle gasket, having size of
4.732cm 4.732cm 4.732cm which are an equilateral triangle used low dielectric
constant substrates with strip feeds to achieve the required bandwidth. Four
such strip feeds iterations are used to achieve bandwidth with return
loss<-10dB, VSWR<2 One advantage observed here at low frequencies the
triangle gives good radiation pattern The antenna has been designed for
operation at WLAN/WiMAX (2.4GHz) and WiMAX (3.5GHz) and also in RADAR for
ultra-wide bandwidth applications.
15:20 A02.6 STUDY OF KOCH MONOPOLE FRACTAL ANTENNA
In
this work, the design of Koch monopole fractal antenna to be used in wireless
communications at the ISM frequency band is presented. Antenna's shape and
dimensions are optimized to achieve area minimization, by applying the
properties of fractal shapes at the radiating slots. The property of
self-similarity that fractal shapes possess has been successfully applied in
other types of antennas with great success. The effects of fractal
miniaturization in this type of antennas, mainly regarding the radiation
pattern, the antenna efficiency, and applicability of fractal shapes in design
of antenna for wireless communication systems are presented herein.
15:40 End of the Session
Session Chairs: Richard Ziolkowski, Nader Engheta, Christophe Caloz
Session BD1
Type Oral Presentation
Schedule Monday, August 15, 13:40-17:20
Room Anadolu Auditorium
13:40 BD1.1 A GENERAL MACROSCOPIC ANISOTROPIC
REPRESENTATION FOR SPATIALLY DISPERSIVE MEDIA
It
is shown that any spatially and temporally dispersive bianisotropic material,
satisfying Maxwell's macroscopic equations for E and H in the Fourier transformed
space, can also be represented as an anisotropic material. Thus, for many
applications, magnetoelectric constitutive parameters can be avoided at the
macroscopic level.
14:00 BD1.2 CONSTRAINTS ON THE TEMPORAL DISPERSION OF
PASSIVE METAMATERIALS
M. Gustafsson, D. Sjoberg, Lund University, Lund, Sweden
Metamaterial
applications such as cloaking, perfect lenses, and artificial permeability are
restricted by the frequency dependence of the permittivity, permeability, and
index of refraction. Here, causality and passivity together with integral
identities for Herglotz functions are used to construct sum rules. The sum
rules relate the frequency dependence of the material parameters with their
high- and low-frequency values. The corresponding physical bounds determine the
minimum variations of the material parameters over a frequency interval. The
results are illustrated with a numerical example for artificial permeability.
14:20 BD1.3 METADISPERSION IN ANISOTROPIC AND
BIANISOTROPIC MEDIA
G. M. Sardi, F. Caminita, E. Martini, S. Maci, University of Siena, Siena, Italy
This
work presents an innovative method for the characterization of metamaterials
dispersion. The attention is focused on structures realized by stacks of planar
periodic surfaces. The analysis procedure subdivides the metamaterial into its
constituent planes, performing a full wave analysis of the single periodic structures,
and uses analytic formulas from Bloch theory to determine the dispersion
characteristics of the overall artificial medium. Physical properties of the
equivalent admittance matrix modeling the single planar sheets are exploited to
analytically describe the dispersion properties of the metamaterial in the
whole first Brillouin zone, starting from a limited number of full-wave
simulations.
14:40 BD1.4 AN EFFICIENT NUMERICAL APPROACH TO THE
ACCURATE ANALYSIS OF PROPAGATION AND RADIATION PHENOMENA IN METAMATERIAL
STRUCTURES
An
overview is presented of a novel implementation for the efficient analysis of
metamaterial structures embedded in layered media. Based on a suitable
mixed-potential integral-equation formulation, ad hoc acceleration procedures
for the periodic potentials (expressed through slowly-convergent series when
source and observation points lie in the same horizontal plane) have been
developed. The approach consists of an asymptotic extraction of
homogeneous-medium terms. Numerical results are shown, proving the
computational efficiency of this method and validating different types of
propagation and radiation features in metamaterial structures. Comparisons are
performed with commercial software and data from the literature.
15:00 BD1.5 AN APPROACH TO FINDING THE CORRECT BRANCH
FROM THE FOREST OF POSSIBLE SOLUTIONS FOR EXTRACTED EFFECTIVE MATERIAL
PARAMETERS
In
the classical Nicolson-Ross-Weir (NRW) electromagnetic material parameter
extraction technique the effective material parameters are obtained through
reflection and transmission measurements of a planar material sample. One of
the advantages of this technique is that it provides the result over a broad
frequency band with just one measurement. This technique, however, does not
provide us unambiguous results of the effective permittivity and permeability
but the correct solution needs to be found through an additional deduction
process. We present a derivative of the NRW extraction technique that can
overcome this problem related to the infinitely many solution branches.
15:20 BD1.6 TRANSFORMATION ELECTROMAGNETICS IN ANTENNA
ENGINEERING: THEORY AND IMPLEMENTATION
Y. Hao, Queen Mary University of London, London, United Kingdom
Current
designs of electromagnetic cloaks are largely based on the use of metamaterials
and a technique called transformation optics/electromagnetics. Free space
cloaks require materials with extreme properties and, hence, they are difficult
to implement in practice. However, the theory of transformation
optics/electromagnetics offers a useful design tool for antenna engineers, and
enables them to develop novel antennas. In this paper, we will review some
research activities at Queen Mary, University of London, regarding applications
of transformation electromagnetics in the antenna and microwave engineering.
Design examples such as flat reflectors, lenses and sub-wavelength antennas
will be introduced.
15:40 Tea/Coffee Break
16:00 BD1.7 TRANSMISSION LINE BASED METAMATERIALS FOR
ACOUSTIC WAVES
We
present our recent work on a one-dimensional acoustic negative refractive index
metamaterial based on the concept of dual transmission line extensively
investigated in microwave engineering. The proposed structure consists of an
acoustic waveguide periodically loaded with membranes realizing the function of
series capacitances and transversally connected open channels realizing shunt
inductances. It exhibits a negative refractive index band over almost one
octave, from 0.6 to 1 kHz. Using formal analogies, we describe how simple
acoustic circuit models can be used for efficient design of metamaterials both
in terms of dispersion and impedance.
16:20 BD1.8 CHIRALITY AND BIANISOTROPY EFFECTS IN
PLASMONIC METASURFACES AND THEIR APPLICATION TO REALIZE ULTRATHIN OPTICAL
CIRCULAR POLARIZERS
A. Alu, Y. Zhao, X.-X. Liu, The University of Texas at Austin, Austin, TX, United States
In
this paper we develop a rigorous analytical theory relating the effective
impedance of plasmonic metasurfaces to a generalized form of polarizability,
which compactly describes the electric, magnetic and magneto-electric response
of the individual inclusions and the overall array coupling. We apply this
theory to the design of plasmonic metasurfaces composed of lithographically
printed planar inclusions, showing that their inherent chiral and bianisotropic
response may be exploited to produce ultrathin optical circular polarizers.
Bianistropic effects, particularly relevant to enhance the response to
circularly polarized light, may be maximized in specific incidence planes, as a
function of the inclusion symmetries.
16:40 BD1.9 FIELD DISPLACEMENT IN A TRAVELING-WAVE
RING RESONATOR META-STRUCTURE
Field
displacement is demonstrated for the first-time in a non-molecular scale
structure, namely a metastructure composed of rings equipped with an isolator.
The structure is explained in terms of rotating magnetic dipole moments and
demonstrated to produce typical gyrotropic field displacement.
17:00 BD1.10 FROM ELECTRONICS TO METATRONICS TO
GRAPHENE METAMATERIALS
N. Engheta, University of Pennsylvania, Philadelphia, Pennsylvania, United States
We
discuss the concept of optical metatronics, i.e., metamaterial-inspired optical
nanocircuitry, in which the metamaterials and plasmonic optics can bring
together three fields of electronics, photonics and magnetics seamlessly under
one umbrella--a paradigm which I call the Unified Paradigm of Metatronics. We
present an overview of our most recent analytical, numerical and experimental
results in developing the optical metatronics. We also show how this concept
can be merged into the platform of graphene, leading to the possibility of
one-atom-thick infrared metamaterials and transformation optics. Future
directions in these topics will also be forecasted.
17:20 End of the Session
C02 – Advanced Architectures of High-Performance Power Amplifiers for Mobile Communications Systems
Session Chairs: Shoichi Narahashi, Nobuyuki Itoh
Session C02
Type Oral Presentation
Schedule Monday, August 15, 13:40-15:40
Room Dolmabahçe A
13:40 C02.1 A CONCURRENT MULTI-BAND POWER AMPLIFIER
WITH COMPACT MATCHING NETWORKS
This
paper presents a novel configuration for a concurrent multi-band power
amplifier (PA). A multi-band matching network comprises a multi-section
impedance transformer that achieves matching in multiple bands. The proposed
impedance transformer provides flexibility in the design of a concurrent
multi-band PA in a wide frequency range. The impedance transformer is compact
since each section comprises a combination of a T-shaped network, a shunt tank
circuit, and a matching element. The proposed 1W-class dual-band PA achieves a
maximum power added efficiency of greater than 53% at 0.8 GHz and 3.3 GHz.
14:00 C02.2 BURST MODE OPERATION AS AN EFFICIENCY
ENHANCEMENT TECHNIQUE FOR RF POWER AMPLIFIERS
B. M. Francois, E. Kaymaksut, P. Reynaert, Katholieke Universiteit Leuven, Leuven, Belgium
In
this paper, the Burst Mode operation is proposed as an efficiency enhancement
technique for RF power amplifiers. It presents an introduction of the burst
mode operation and the efficiency of Burst Mode RF power amplifiers is
summarily analyzed. The efficiency improvement for a wideband load and a narrow
band filter are both illustrated. To demonstrate the validity of the proposed
Burst Mode operation, a PCB-mounted Burst Mode PA using a LDMOS transistor has
been fabricated. Measurements show a peak efficiency of 78\% and 28.5dBm output
power and an efficiency of 49.5\% at 6dB power back-off.
14:20 C02.3 ASIC IMPLEMENTATION OF FREQUENCY DOMAIN
EQUALIZER FOR SINGLE CARRIER TRANSMISSION
Since
SC-FDE with MMSE operates at lower PAPR than OFDM, SC-FDE with MMSE is a main
candidate for uplink of cellular system such as LTE. In this paper, an ASIC chip
for the SC-FDE is implemented on TSMC 180 nm CMOS. The chip size is 5.86 mm^2.
The power consumption is 200 mW at data rate of 4.86 Mbit/s. In the condition
of 16 paths uniform power delay profile, at a BER of 10^-4, the degradation of
measured Eb/N0 from computer simulation is found to be less than 1 dB.
14:40 C02.4 A 3.5-GHZ BAND 140-W-CLASS WIDEBAND
FEED-FORWARD POWER AMPLIFIER FOR MOBILE BASE STATIONS
Y. Suzuki, J. Ohkawara, S. Narahashi, NTT DOCOMO, INC., Yokosuka, Japan
This
paper analyzes the characteristics when compensating for wideband
intermodulation distortion (IMD) components of a fabricated 3.5-GHz band 140-W
class feed-forward power amplifier (FFPA). The fabricated FFPA achieves the
bandwidths of 160 MHz and 120 MHz when compensating for the IMD components for
LTE signals with the bandwidths of 5 MHz and 20 MHz. Experimental and analysis
results show that the FFPA compensates for the wideband IMD components when the
IMD component compensation level is reduced. This paper shows that the FFPA is
a worthwhile linearizer that compensates for 3.5-GHz band wideband IMD
components.
15:00 C02.5 HAMMERSTEIN PREDISTORTER FOR HIGH POWER RF
AMPLIFIERS IN OFDM TRANSMITTERS
OFDM
(Orthogonal Frequency-Division Multiplexing) is a wideband digital modulation
scheme which is critically dependent on linearity in the hardware system, due
to its reliance on Fourier Transformation and its inherently high
peak-to-average power ratio (PAPR), and minimization of nonlinearity is thus a
priority. In this paper the effectiveness of a predistortion based on the
Hammerstein model is investigated by measurement of Error Vector Magnitude
(EVM) in AWGN channel and Adjacent Channel Power Ratio (ACPR). Accuracy of
prediction of Power amplifier (PA) nonlinearity with memory effect and baseband
predistorter is investigated by the experimental results.
15:20 C02.6 ADAPTIVE BIAS LINC ARCHITECTURE FOR
WIRELESS TRANSMITTERS
S. Lin, A. E. Fathy, University of Tennessee, Knoxville, United States
A
novel adaptive bias LInear amplification with Nonlinear Components (LINC)
transmitter is introduced and simulated. Where predistortion is applied to the
baseband signal; thus the bias of the high efficient power amplifier (PA) is
adaptively changed according to the envelop distribution of the modulated
baseband signal and the PA itself. This novel transmitter can simultaneously
achieve relatively high average efficiency and linearity even with a high
peak-to-average (PAR) signal. A comprehensive simulation framework has been
developed to validate this adaptive bias scheme with 16, 32, and 64 QAM
signals, which have higher than 5 dB PAR levels.
15:40 End of the Session
DB1: Modeling of High Frequency Devices and Circuits
Session Chairs: Peter Russer, Irsadi Aksun
Session DB1
Type Oral Presentation
Schedule Monday, August 15, 13:40-17:20
Room Dolmabahçe B
13:40 DB1.1 VESELAGO-PENDRY SUPERLENS IMAGING MODELED
WITH A SPECTRAL WAVEGUIDE APPROACH
A
spectral waveguide model of a superlens imaging system is presented. This model
offers advantages in the analysis of dynamics and reality effects and in
accurate numerical simulation. Insights into the dynamic response of the
superlens, gained from both theoretical and numerical studies, are presented. The
effect of loss on the dynamic properties is investigated. In addition, the
proposed model leverages a wealth of expertise available for the design of
filters, artificial dielectrics and backward wave structures and could possibly
aid in the engineering of practical super-resolution imaging systems that will
be an enabling technology for future nanoelectronics systems.
14:00 DB1.2 LIQUID RF ANTENNAS, ELECTRONICS AND
SENSORS: A MODELING CHALLENGE
A. Traille, M. M. Tentzeris, Georgia Tech, Atlanta, United States
In
this paper we present a novel approach for the modeling of multi-phase liquid
RF electronics and sensors problems. The deployment of level-set based
multi-phase simulation could potentially lead to the development of a new
generation of computationally efficient approaches that could bridge the gap
between Maxwell and solid/liquid-interface equations. Numerous examples of
liquid antennas and solid/liquid wireless biosensors will be presented at the
conference to verify the accuracy and validity of the above approach in a
variety of liquid radio-frequency wearable, implantable and printable
topologies.
14:20 DB1.3 SPATIAL AND TEMPORAL MODELING OF FEW-CYCLE
TI:SAPPHIRE LASERS
In
few-cycle Kerr-lens mode-locked Ti:sapphire lasers, the laser crystal is
exposed to extremely high intensities which can induce crystal damage. Modeling
of the intracavity pulse dynamics can deepen the understanding of the different
phenomena contributing to damage and how to best optimize the laser
performance. We present a one-dimensional laser model based on dispersion
managed mode-locking that accurately captures the temporal and spectral
intracavity dynamics and reproduces the output characteristics in great detail.
Furthermore, a spatiotemporal model is introduced that incorporates plasma formation
to simulate the spatial beam propagation in agreement with experimental
observations.
14:40 DB1.4 ACCURATE PHOTONIC ANALOG-TO-DIGITAL
CONVERSION
Photonic
analog-to-digital converters (ADCs) are attracting significant interest due to
promise of overcoming the problem of aperture jitter and improving ADC
performance level by orders of magnitude. This work examines several critical
factors which define the accuracy of an optically-sampled
wavelength-demultiplexed ADC built on a silicon chip using silicon photonic
technology. These factors are the optical power-dependent shot noise, optical
power-dependent nonlinearities due to two-photon and free-carrier absorption in
silicon, and nonlinear transfer function of a silicon modulator. Ways to reduce
the impact of these factors on ADC accuracy are considered.
15:00 DB1.5 FAST AND ACCURATE DESIGN METHODOLOGY FOR
MILLIMETER-WAVE INTEGRATED CIRCUITS
In
this paper the design of integrated passive and active circuits in silicon by
use of rigorous electromagnetic analysis. A broadband directional coupler has
been designed with large bandwidth at 110 GHz center frequency and measured
from 20 to 140 GHz. The simulation is compared to measurement showing very good
agreement. A VCO has been designed at 116 GHz center frequency. The measurement
of the center frequency is within 1% of simulation. The design methodology for
a 240-GHz power detector also is given showing the design of a L-type matching
network.
15:20 DB1.6 SELF-CONSISTENT SIMULATION OF LOCAL
POTENTIAL IN EXTERNAL-GATE BIASED GRAPHENE NANORIBBONS
We
report on the self-consistent analysis of armchair graphene nanoribbon (GNR)
field-effect transistors (FET), in the case of multi-band coherent carrier
transport. In principle, the same approach can be extended to include the
contribution to charge transport due to different layers of a few-layer
GNR-FET. To the aim of demonstrating the versatility of our simulation tool, we
provide interesting examples about the dependence of charge and self-consistent
potential on the gate voltage, for small drain voltages: these include details
of numerical convergence of the iterative system of Poisson and
Schrӧdinger equations
15:40 Tea/Coffee Break
16:00 DB1.7 AC CONDUCTIVITY OF METALLIC CARBON
NANOTUBES (CNTS) EXPOSED TO A DC FIELD
The
AC conductivity of a carbon nanotube (CNT) is derived and it is shown that it
can become negative when the CNT is exposed to a DC axial field in addition to
the AC field. For this purpose, the Boltzmann transport equation (BTE) is
solved within the relaxation time approximation (RTA) by separating the AC and DC
contributions. The AC carrier distribution and the AC conductivity are found
via a semi-analytical procedure. Absolute negative AC conductivity is found for
a DC field above 10^5 V/m, which is a promising result toward enabling CNT
traveling-wave amplifiers.
16:20 DB1.8 EQUIVALENT CIRCUIT SYNTHESIS FOR
MICROSTRIP STRUCTURES DESIGN AND OPTIMISATION
The
paper suggests network synthesis algorithm used limited band scattering
parameters of microwave devices. Presentation of the model in the form of an
equivalent electric circuit maintains its feasibility as a microwave device
under variation of parameters in the process of optimization. The proposed
approach is based on the simple description of the microwave structures using
lumped element network. The submitted example of synthesis illustrates the
microstrip filter design.
16:40 DB1.9 MICROMACHINED J-BAND RECTANGULAR WAVEGUIDE
FILTER
M. Vahidpour, K. Sarabandi, University of Michigan, Ann Arbor, MI, United States
Fully
micromachined waveguide filters are realized based on metal E-plane rods. The
rods make a series of shunt inductors separated by the length of the waveguide.
Two- and three- pole filter designs for 230~245 GHz bands constructed in WR-3
waveguide are introduced. The filters are microfabricated by etching the rods and
waveguides on one silicon wafer which later is bonded with another metal-coated
wafer. The devices are measured using a J-band S-parameter test and the
measurement results are in good agreement with the simulation results.
17:00 DB1.10 INFINITE INTEGRALSWITH THEWEIGHTED
AVERAGES ALGORITHM
J. R. Mosig, A. G. Polimeridis, EPFL, Lausanne, Switzerland
A
new version of the weighted averages (WA) algorithm, called generalized WA, is
introduced. Generalized WA exhibit a more compact formulation, devoid of
iterative and recursive steps, and a wider range of applications. It is more
robust, as it provides a unique formulation, valid for real and imaginary
parameters. The implementation of the new version is easier and more efficient.
Preliminary numerical examples show the promise of the generalized WA that
become the most interesting version among the generic class of WA algorithms,
which are currently recognized as the most competitive algorithms to evaluate
Sommerfeld integral tails.
17:20 End of the Session
E02 – Lightning and Related Effects I
Session Chairs: Vladimir A. Rakov, Z. Kawasaki
Session E02
Type Oral Presentation
Schedule Monday, August 15, 13:40-17:20
Room Galata
13:40 E02.1 LIGHTNING RETURN STROKES TO TALL TOWERS:
ABILITY OF ENGINEERING MODELS TO REPRODUCE NEARBY ELECTROMAGNETIC FIELDS
We
present measurements of nearby vertical and horizontal electric fields from
leaders and return strokes associated with lightning strikes to the 100-m tall
Gaisberg Tower in Austria obtained in 2007 and 2008. The fields were measured
at a distance of about 20 m from the towers vertical axis. Simultaneously with
the fields, return-stroke currents were also measured at the top of the tower.
The measured data are used to test engineering models for the return stroke. In
general, the agreement between measured waveforms and model-predicted ones are
satisfactory.
14:00 E02.2 FDTD SIMULATION OF FIELD-REDUCTION EFFECT
AT GROUND DUE TO CORONA AT LIGHTNING-TRIGGERING WIRE
The
effect of an upward-extending wire used for artificial lightning initiation
from thunderclouds and the corona space charge emanated from this wire on the
close electric field (prior to lightning initiation) on the ground has been
examined using the FDTD method. When the wire-top altitude is 200 m, the
reduction of upward-directed electric field at a horizontal distance of 60 m is
15, 23, 28, and 38% relative to the background value at ground surface of 10
kV/m for corona radii, 0.27, 2, 4, and 10 m, respectively. These calculated
results agree well with measurements.
14:20 E02.3 INFLUENCE OF RETURN STROKE SPEED AND
LEADER LINE CHARGE DENSITY ON LIGHTNING CORONA SHEATH DYNAMICS
Positive
transferred charge inside the lightning channel core during the return-stroke
stage dominates the total charge when the speed of the return stroke current
wave is relatively low and negative leader line charge density is less than
typical values inferred from field measurements. As a result, the positive
charge inside the channel during the return-stroke stage can be temporarily
greater than the negative charge deposited by the preceding leader. This may
explain significant positive overshoots in radial electric fields measured with
a Pockels sensor close to the triggered lightning channel at ground.
14:40 E02.4 LIGHTNING ELECTROMAGNETIC FIELDS AND
INDUCED VOLTAGES: INFLUENCE OF CHANNEL TORTUOSITY
Models
for calculation of lightning induced overvoltages usually assume a straight and
vertical lightning channel. However, it is well known that the lightning path
is tortuous on scales ranging from 1 m to 1 km. In this paper the tortuosity
effect is analyzed for both lightning-generated electromagnetic fields and
induced voltages. For a schematic representation of tortuous lightning channel,
it is shown that at close and intermediate ranges the predominant effect is due
to the inclination of the lowest channel segment; only for fields at relatively
far ranges the overall tortuosity effect becomes appreciable.
15:00 E02.5 RADIO-PHYSICAL METHODS OF ANALYSIS FOR
THUNDERSTORM FIELD PERTURBATIONS
Complex
field experiments have been undertaken on the basis of the observational set-up
arranged in the Upper-Volga Region during the convective seasons of 2005-2010.
Spectral and statistical characteristics of electric field perturbations in the
vicinity of thunderstorm clouds have been investigated. Statistical analysis
allowed us to relate found peculiarities with different stages of thunderstorm
generator dynamics. We develop our fractal simulation code to take into account
the spatio-temporal dynamics of a cloud discharge, to compare the results with
the observations and to address several actual problems of lightning initiation
physics.
15:20 E02.6 STEPPED LEADER CHARACTERISTICS IN
DEVELOPING HORIZONTALLY WITHIN THUNDERCLOUDS AND IN DESCENDING OUT OF
THUNDERCLOUDS
We
examine VHF and optical images of cloud-to-ground flashes to study IC leaders
that propagated within thunderclouds and CG leaders that descended outside
thunderclouds. It is shown that IC leaders developed smoothly and CG leaders
propagated in a heavily branched manner. We speculate that, in the case of IC
leaders, only the leader tip having the highest charge density in the channel
could propagate in E-field intensified by local positive charge. In the case of
CG leaders, not only leader tips but also lower parts of the leader could
initiate new branches due to higher charge density.
15:40 Tea/Coffee Break
16:00 E02.7 DEVELOPMENT OF THE BROADBAND RADAR NETWORK
WITH HIGH RESOLUTION
A
small-baseline weather radar network consisting of the Ku-band broadband radars
(BBR) for meteoro-logical application is developed. The BBR is a remarkably
high-resolution close-range Doppler radar designed for detecting and analyzing
rapidly evolving weather phenomena such as severe thunderstorms, tornadoes, and
downbursts, which often cause damage to our lives seriously. A radar network
with several BBRs (the BBR network) observes multi-directionally and
simultaneously these severe phenomena with high reso-lution and accuracy. In
this presentation, the concept of the project and the initial observation
results of the BBR network were presented.
16:20 E02.8 A MACROMODEL-BASED ALGORITHM FOR THE
CALCULATION OF LIGHTNING RADIATED ELECTROMAGNETIC FIELDS AND INDUCED VOLTAGES
IN TRANSMISSION LINES
In
this paper, we propose a fast and efficient algorithm for the calculation of
lightning radiated electromagnetic (EM) fields in the space. These
macromodel-based calculations will be done using a mixed time-frequency domain
method. Vector Fitting algorithm is employed to trace the poles/residues
position of the channel-base current-radiated electromagnetic fields system
transfer function in different points of the space. The spatial representation
of the poles and residues locations will result in efficient calculation of the
induced voltage on the frequency dependent multiconductor transmission lines
(MTL) over a lossy ground.
16:40 E02.9 EVALUATION OF THE COORAY-RUBINSTEIN
FORMULA FOR DISTANCES FARTHER THAN A FEW KILOMETERS USING THE PARALLEL FDTD
METHOD
M. Khosravi Farsani, R. Moini, S. H. H. Sadeghi, Amirkabir university of technology, tehran, Iran
a
parallel finite difference time domain code is developed for the calculation of
the horizontal electric field above ground for three distances of 2 Km, 5 Km
and 10 Km from the return stroke channel. An electromagnetic model of lightning
is adopted for the purpose of simulation. The obtained results are compared
with those simulated by Cooray-Rubinstein formula (CR). The effect of ground's
conductivity on the electric field value is also investigated. The results show
that the accuracy of CR formula decreases as the grounds conductivity decreases
or distance of observation point from the lightning channel becomes larger.
17:00 E02.10 AN IMPROVED DISTANCE FINDING TECHNIQUE FOR
SINGLE-SITE LIGHTNING LOCATION SYSTEM USING REFLECTION CHARACTERISTICS OF THE
ANISOTROPIC IONOSPHERE
M. Ozaki, S. Yagitani, K. Miyazaki, I. Nagano, Kanazawa University, Kanazawa, Japan
The
distance finding technique for a single-site lightning location system is
evaluated by using theoretical sferics, which are calculated under the effect
of the magnetized ionosphere. The calculated ionospheric reflection
coefficients are stable at smaller incident angles, while they exhibit a poor
reflection at larger incident angles around 70 degrees. The distance finding
accuracy is improved when the 1st reflected pulse of the sferic having the
largest incident angle is excluded in the estimation. The errors of the
improved distance finding technique become less than 5%, while those of the
previous technique using the 1st reflected pulse were 20%.
17:20 End of the Session
F02 – Attenuation and Depolarization in Satellite and Terrestrial Propagation
Session Chair: Bertram Arbesser-Rastburg
Session F02
Type Oral Presentation
Schedule Monday, August 15, 13:40-17:20
Room Haliç
13:40 F02.1 STATISTICS OF RAIN ATTENUATION REVISITED
Millimeter
frequency satellite links are prone to variations in attenuation over a large
range, more than 30 dB. This has been considered to be caused by meteorological
conditions. Statistical distributions have been fit-to-data with little or no
physical insight. It is the purpose of this paper to test the hypothesis that
the dynamic variations are Ricean or Rayleigh type fading, caused by multipath
from the rain. This opens the possibility of exact distributions of Doppler
variations and of the recently studied rain fade slope, which follows a
Students t- distribution with the Doppler spread as parameter
14:00 F02.2 PREDICTING THE PROPAGATION LOSS THROUGH A
TREE CANOPY AT MILLIMETER FREQUENCIES FORWARD SCATTERING APPROXIMATION 3-D
VECTOR RADIATIVE TRANSPORT THEORY
The
vector radiative transport theory is used to compute the attenuation produced
by a tree canopy containing random located lossy-dielectric leaves and branches
at millimeter wave frequencies. The forward scattering approximation is used to
simplify the radiative transport equation. The forward scattering approximation
is used since at millimeter frequencies, the leaves and branches are large and
thick compared to the wavelength; hence, a leaf or a branch scatter energy
strongly in the forward direction and weakly in all other directions. Leaves
are modeled as flat-circular lossy-dielectric discs and branches as
lossy-dielectric cylinders with prescribe orientation statistics.
14:20 F02.3 COMPUTATION OF RAIN ATTENUATION IN
TROPICAL REGION WITH MULTIPLE SCATTERING AND MULTIPLE ABSORPTION EFFECTS USING
EXPONENTIAL DROP SIZE DISTRIBUTION
Rain
attenuation causes scattering and absorption of electromagnetic waves and could
be a significant problem in radio propagation, especially in tropical region
which has high rainfall rate. In this paper, raindrop was modeled using
exponential raindrop size distribution and computed with multiple scattering
and multiple absorption effect previously derived. It was assumed that raindrop
shape is spherical and has dielectric constant following the Double Debye
Model. Based on the analysis, rain attenuation effects become significant for
frequencies above 10 GHz and reach the peak at about 125 GHz. Other important
results are also reported.
14:40 F02.4 KU-BAND SIGNAL DEPOLARIZATION OVER
EARTH-SPACE PATH IN RELATION TO SCATTERING OF RAINDROPS AT A TROPICAL LOCATION
A. Maitra, A. Adhikari, University of Calcutta, Kolkata, India
The
depolarization of a satellite signal due to scattering by rain drops has been
studied at a tropical location. The depolarization phenomenon is observed in
terms of an enhancement of cross-polar component of a horizontally polarized
Ku-band signal. The differential phase shifts, dominantly responsible for
causing depolarization at Ku-band due to scattering by spheroidal raindrops,
are computed by employing the point matching technique and using experimentally
obtained rain drop size distribution (DSD) data. The differential phase shift
is significant for large drops (> 3mm). Consequently, DSD plays an important
role in determining the depolarization of the satellite signal.
15:00 F02.5 TWO YEAR RAIN ATTENUATION STATISTICS OVER A
LINE OF SIGHT TERRESTRIAL MICROWAVE LINK OPERATING AT 30 GHZ IN TROPICAL REGION
AMRITSAR (INDIA)
P. Sharma, Model Institute of Engineering and Technology, Jammu, Jammu and Kashmir, India
The
precipitation in path of microwave communication links leads to fading of
signal. The calculation of fade margin for 99.99 % of the time-availability of
such links requires the knowledge of rain rate and attenuation levels for 0.01
% time of year. The ITU-R has given recommendations regarding rain rate and
attenuation levels but it has been found that the recommendations are not
suitable for tropical regions. The paper presents the experimental results of
two year rain attenuation measurement program conducted in a tropical site
Amritsar (India). The experimental results are different from that predicted by
ITU-R.
15:20 F02.6 SOME MELTING LAYER CHARACTERISTICS AT TWO
TROPICAL LOCATIONS IN INDIAN REGION
S. Das, A. Maitra, University of Calcutta, Kolkata, West Bengal, India
Hydrometeors
pose serious threat to satellite communication operating above 10 GHz. The
designing line-of-sight link usually is based on the ITU-R models, which are
often inadequate for tropical region. ITU-R model uses a yearly averaged
constant rain height for the attenuation calculation, which may not be valid
for tropics. This paper reports the study of rain height based on Micro Rain
Radar and Radiosonde observations at two tropical locations in Indian region.
Results suggest a possible modification in the rain attenuation model taking
into account the melting layer height variation with the season and rain rate.
15:40 Tea/Coffee Break
16:00 F02.7 ANALYSIS OF RAINDROP SIZE DISTRIBUTION
CHARACTERISTICS IN MALAYSIA FOR RAIN ATTENUATION PREDICTION
Variability
of rainfall characteristics in the equatorial regions is a key problem in
estimating adequate fade margin due to rain attenuation in satellite
communication. Based on disdrometer data collected in Kuala Lumpur, Malaysia,
this paper investigates the characteristics of the raindrop size distribution
(DSD) and the dependence of rain attenuation on the DSD. Its diurnal variation
and the role of critical diameter values on the estimation of specific
attenuation are also discussed. Preliminary results suggest that satellite
links operating in the afternoon and early evening hours should be provided
with an extra fade margin to compensate for rain attenuation impairments.
16:20 F02.8 DIMENSIONAL STATISTICS OF RAINFALL
SIGNATURE AND FADE DURATION FOR MICROWAVE PROPAGATION IN NIGERIA
As
the communication services are increasingly demanding more access for higher
frequencies up to Ka-band and beyond, dimensional statistics of rainfall for
predicting rain induced attenuation is required for estimating the link budget
and the communication performance. Attenuation due to rain restricts the path
length of radio communication systems and limits the usage of higher
frequencies for terrestrial point-to-point microwave links and satellite
communications. In this paper, some results of dimensional statistics of
rainfall signature and fade duration are presented. Rain events are studied to
examine the efficacy of predicting the attenuations from point rain rate
measurements
16:40 F02.9 GENERATION OF AN EMPIRIC PROPAGATION MODEL
FOR FOREST ENVIRONMENT AT GSM900/GSM1800/CDMA2100
This
paper represents a generation of an empiric propagation model for a certain
pine tree environment. An empiric model has been obtained by the addition of
vegetation loss factor L into the free space model by using both forest and
open area measurements. Three different models for different operating band
have been generated. The model error increased with frequency from 900MHz to
1800MHz, but it reached smallest value at CDMA2100. This could be a result of
large (5MHz) bandwidth of CDMA2100. For better models, curve fitting techniques
can be used to determine L as a function of tree number.
17:00 F02.10 TO THE PROBLEM OF ELECTROMAGNETIC WAVES
PROPAGATION IN TURBULENT MAGNETIZED PLASMA SLAB
Second
order statistical moment of the ordinary and extraordinary waves scattered by
turbulent magnetized plasma slab with electron density and magnetic field
fluctuations is analytically calculated applying the perturbation method.
Numerical calculations are carried out for the anisotropic Gaussian fluctuation
spectrum at different anisotropy factor and the angle of inclination of prolate
irregularities with respect to the external magnetic field. Phase portraits of
correlation function of the phase and amplitude fluctuations of scattered
radiation are constructed. It is shown that correlation between ordinary and
extraordinary wave decreases in proportion to the anisotropic factor.
17:20 End of the Session
G02 – Measuring and Modeling the Ionospheric Electron Density Profile
Session Chairs: Dieter Bilitza, B Zolesi, Bodo Reinisch
Session G02
Type Oral Presentation
Schedule Monday, August 15, 13:40-17:20
Room Topkapi A
13:40 G02.1 OPTIMIZATION OF F2 LAYER PARAMETERS USING
IRI-PLAS AND IONOLAB-TEC
In
this study, the relation of the maximum ionization height (HmF2) and the
critical frequency (FoF2) of F2 layer is examined within their parametric range
through the International Reference Ionosphere extended towards the
plasmasphere (IRI-Plas) model and the IONOLAB-TEC. HmF2 and FoF2 are optimized
using an iterational loop through Non-Linear Least Squares method. HmF2 and
FoF2 are obtained for various locations including Turkey for the same quiet
day. Results are compared with ionosonde data where available. This study
enables the modification and update of empirical and deterministic IRI Model to
include instantaneous variability of the ionosphere.
14:00 G02.2 A NEW VARY-CHAP MODEL OF TOPSIDE ELECTRON
DENSITY PROFILES BASED ON ISIS-2 DATA
A
new model of the topside electron density distribution is developed for IRI.
The new Vary-Chap function is a generalized Chapman profile with a continuously
varying shape function S(h): N/Nm = 1/S^2 {exp[(1-Y-exp-Y)/2]} with Y an
integral function of S(h). This equation is solved for S(h), and S(h) functions
for 80,000 ISIS-2 profiles are calculated. A parameterized function S*(h) is
fitted to each shape function characterizing the shape of the profiles without
direct dependence on hm and NmF2.
14:20 G02.3 INVESTIGATION OF THE BOTTOMSIDE / TOPSIDE
CONTRIBUTION TO THE TOTAL ELECTRON CONTENT AT EUROPEAN MID-LATITUDES
The
electron density profiles, derived from FormoSat-3/COSMIC radio occultation
measurements and European mid-latitude ionosondes Pruhonice and Juliusruh, were
analyzed in order to compare the contribution of bottomside and topside
ionosphere to the GPS-derived total electron content. Analysis was carried out
for different seasonal conditions during period of low solar activity; special
attention was focused on the differences in these parts contribution to total
electron content for night and daytime hours.
14:40 G02.4 MEASUREMENTS AND IRI MODEL PREDICTIONS
DURING THE RECENT SOLAR MINIMUM
Comparisons
of CHAMP and GRACE electron density measurements with predictions of the URSI
International Reference Ionosphere (IRI) have shown significant differences
during the recent extended solar minimum, while ionosonde data do not seem to
show differences of similar magnitude. We have further evaluated the
performance of IRI during this period using C/NOFS PLP data and ionosonde data
from middle and low latitude stations. We also study the impact of
uncertainties in the predictions of solar indices on the IRI densities.
15:00 G02.5 SPATIAL AND TEMPORAL VARIABILITY OF THE
LOW- AND MID-LATITUDE IONOSPHERE AS REVEALED BY MODAL DECOMPOSITION
We
examine two approaches to capture the modes of spatial and temporal variability
observed in the ionosphere: 1. decomposition into modes as functions of local
time and zonal wavenumber and 2. analysis using empirical orthogonal function
decomposition and the corresponding principal component analysis technique. The
spectral analysis of the different time series of reveals how different
mechanisms such as solar flux variation, change of the orbital declination,
nonlinear mode coupling and geomagnetic activity are separated and expressed in
different modes. We also perform similar analysis performed on output from the
TIE-GCM to provide insight on the observed phenomena.
15:20 G02.6 STATISTICAL ANALYSIS OF IONOSPHERIC
ACTIVITY IN THE PERIOD OF LOW SOLAR ACTIVITY USING DPS-4 IONOSONDE DATA
In
investigation of fundamental problems of ionosphere physics always large
attention was given to the observational data during low solar activity, when
there was a capability to minimize influence of external factors. On the basis
of regular, continuous measurement of the Irkutsk ionospheric sounder the
automated method of researches of ionospheric disturbances was designed.
Statistical analysis of disturbances of an electron concentration during 2004 -
2009 was done. Main problem of the analysis was determination of total number
of perturbed days and determination of total number of wave disturbances
depending on a level of solar activity, season and time.
15:40 Tea/Coffee Break
16:00 G02.7 INTEGRATION OF MULTI INSTRUMENT
IONOSPHERIC PLASMA DIAGNOSTICS USED FOR NEAR EARTH ENVIRONMENTAL MODELLING
The
aim of this presentation is to show global distribution of plasma parameters
diagnosed by various measuring techniques as: in situ wave and plasma
diagnostics registered on board of DEMETER satellite, GPS IGS/EPN network, GPS
Antarctic and Arctic IGS observation and the data retrieved from FORMOSAT-3/COSMIC
measurements. We are willing to present and validate the properties of the
ionospheric electron density profiling retrieved from FORMOSAT-3/COSMIC radio
occultation measurements. We would like also to discuss the limitation of
presented diagnose techniques with respect to different geomagnetic condition
and localisation in space.
16:20 G02.8 3-D INVERSION OF IONOSONDE DATA FOR
IONOSPHERIC ELECTRON DENSITY: NEW DEVELOPMENTS AND BENEFITS FOR ASSIMILATIVE
MODELING
N. A. Zabotin, University of Colorado at Boulder, Boulder, CO, United States
Modern
phase-based digital ionosondes have capabilities to measure accurately both the
group time of propagation and the directions of arrival for each ionogram echo.
Inversion algorithm NeXtYZ uses this information to recover locally both true
vertical profile and horizontal gradients of ionospheric plasma density. For
the first time in ionospheric sounding practice this algorithm provides justifiable
profile uncertainties that characterize specific ionogram and obey Gaussian
statistics. Horizontal gradients not only describe the plasma density
distribution directly but also quantify energetics and dynamics of the
ionosphere and thermosphere through characterization of the gravity waves and
of the neutral wind.
16:40 G02.9 MONITORING D-REGION VARIABILITY FROM
LIGHTNING MEASUREMENTS
In
situ measurements of ionospheric D-region characteristics are somewhat scarce
and rely mostly on sounding rockets. Remote sensing techniques employing Very
Low Frequency (VLF) transmitters can provide electron density estimates from
subionospheric wave propagation modeling. Here we discuss how lightning
waveform measurements, namely sferics and tweeks, can be used for monitoring
the D-region variability and day-night transition, and for local electron
density estimates. A brief comparison among D-region aeronomy models is also
presented.
17:00 G02.10 MODELING IONOSPHERIC PROPAGATION OF LOW
FREQUENCY SIGNALS FOR REMOTE SENSING PURPOSES USING CHARGE DENSITY PROFILES
E. D. Schmitter, University of Applied Sciences Osnabrueck, Osnabrueck, Germany
The
use of powerful low frequency transmitter signals is a well established
technique for remote sensing of the lower ionosphere. Standard tools for
calculating propagation conditions like the Long Wave Propagation Capability
(LWPC) code - rely on default procedures for modeling the day-night transition
conditions that do not map reality sufficiently for modeling purposes. We
propose an improved method by making use of the possibility to introduce charge
density profiles into the LWPC that vary appropriately over the day-night cycle
and additionally can model disturbances caused by forcing of the lower
ionosphere from above and below.
17:20 End of the Session
Session Chair: Bertrand Lembège
Session H02
Type Oral Presentation
Schedule Monday, August 15, 13:40-17:20
Room Topkapi B
13:40 H02.1 DYNAMICS OF QUASI-PERPENDICULAR SHOCKS:
RECENT RESULTS ISSUED FROM 2D PIC SIMULATION
Cross-scale
coupling between fluid dynamics and particle kinetics at perpendicular
collisionless shocks is an issue of space plasma physics. The influence of
shock-front ripples to the dynamics of shocks is studied by means of a
large-scale two-dimensional (2D) full particle-in-cell (PIC) simulation. The
present simulation has confirmed the transition of shock structures from the
cyclic self-reformation to the quasi-stationary shock front due to rippled
structures at the shock front.
14:00 H02.2 MICROTURBULENCE AT THE FRONT OF
SUPERCRITICAL QUASIPERPENDICULAR SHOCKS
The
drift of the reflected ion beam versus the electrons across the magnetic field
can easily destabilize waves in the electron cyclotron frequency range. Several
Bernstein harmonics can be unstable, depending upon the ion beam's drift and
temperature. With electromagnetic PIC simulations we investigate their
nonlinear characteristics. First, high harmonics develop in agreement with
dispersion properties. Second, an inverse cascade occurs whereby the spectrum
shifts toward lower k-modes to eventually accumulate on the first harmonic. The
late phase showcases a magnetic component to the spectrum and a significant
energy transfer from the ion beam to the electrons.
14:20 H02.3 A COMPARATIVE ANALYSIS OF TERRESTRIAL AND
PLANETARY BOW SHOCKS
H. Kucharek, University of New Hampshire, Durham, NH, United States
Shocks
are spectacular and energetic events in the Universe. Generated by supernovae,
stellar winds, and the solar wind they have important effects. They are
accelerators and they act on galactic nebula triggering formation of planetary
systems. The Earths bow shock results from the interaction of the solar wind
with the magnetosphere. Being a prime science objective of many missions it has
been studied in detail. We now obtained data from Mercury, Venus, Mars,
Jupiter, and Saturn. In this presentation we will review similarities and
differences of these shocks in shape, topology, solar wind interaction and
highlight key science questions.
14:40 H02.4 NONLINEAR MIRROR MODE STRUCTURES IN
MULTI-DIMENSIONAL MODELS
We
obtain the difference of the mirror mode magnetic structures between 2D and 3D
hybrid simulations. The magnetic dip structure can be found only in the 2D
model with low ion beta conditions. In the 3D model or 2D model with high ion
beta, we obtain the magnetic peak structures. From the pressure balance
condition between the magnetic field and the protons, how the difference of the
magnetic structures in the 2D model between the ion betas occurs is shown.
15:00 H02.5 THEMIS-DOUBLE STAR-CLUSTER OBSERVATIONS OF
RECONNECTION AND DYNAMICS ACROSS THE DAYSIDE MAGNETOPAUSE.
M. W. Dunlop, RAL, STFC, DIDCOT, United Kingdom
Study
of the extent across the Earths magnetopause of magnetic reconnection (MR) has
recently benefitted from an unprecedented growth in complexity of multi-point,
in situ measurements, on the small and meso-scale. Nevertheless, direct
measurements of the small active region are still relatively rare, owing to the
time variable nature of the near-Earth environment. We report direct evidence
of X-line structure resulting from MR at widely separated locations and a full
traversal through a reconnection layer. Observations are taken from conjunctions
of 4-Cluster, 5-THEMIS and the Double Star, TC-1 spacecraft.
15:20 H02.6 MAGNETOHYDRODYNAMIC SIMULATIONS OF THE
MAGNETOPAUSES OF SATURN, JUPITER AND THE EARTH
We
use global magnetohydrodynamic simulations to compare the responses of Saturn,
Jupiter and the Earth to the solar wind. We investigate the magnetospheric
boundaries in the presence of dayside reconnection and find waves on the
boundary that are consistent with the Kelvin-Helmholtz (K-H) instability. At
the Earth and Jupiter reconnection erodes the dayside magnetopause but there is
little erosion at Saturn. The waves at Earth are caused by solar wind velocity
shear. At Saturn the solar wind velocity shear combines with rotating Kronian
plasma to create the waves. At Jupiter rotating Jovian flows cause the
instability.
15:40 Tea/Coffee Break
16:00 H02.7 PLASMA TRANSPORT PROCESSES AT THE HIGH
LATITUDE MAGNETOSPHERE OBSERVED BY CLUSTER
Cluster
four spacecraft data is used to study the spatial-temporal characteristics
in/near the high and mid-altitude cusp under northward IMF. In our previous
work a transition layer equatorward of the cusp was observed, which is
suggested to be the entry layer during northward IMF. From event study and a
further survey tailward of the Cusp, some transport processes of sheath-like
ions in the magnetosphere are studied. Possible (dual) lobe reconnection model
in the northward IMF condition are applied to explain these observations.
16:20 H02.8 THE ACCELERATION OF ELECTRONS IN THE
MAGNETOTAIL AND THEIR AURORAL SIGNATURES
By
using data from the THEMIS and Cluster missions together with global
magnetohydrodynamic and large scale kinetic particle simulations, we
demonstrated that electrons were energized by two distinct mechanisms: betatron
acceleration and reconnection processes. The simulation results were validated
by comparing the electron energy flux at the equatorial plane with THEMIS
observations. To determine the auroral signatures of these processes we
calculated the corresponding precipitating electron energy fluxes at different
times. We found a direct correspondence between the earthward movement of the
dipolarization fronts and the location of the precipitating energy flux.
16:40 H02.9 STOCHASTIC FERMI ACCELERATION IN THE
EARTH'S MAGNETOTAIL CURRENT SHEET: NUMERICAL STUDIES
S. Perri, A. Greco, G. Zimbardo, Universita' della Calabria, Rende, Italy
We
show results from 2D and 3D test particle simulations investigating the
acceleration of protons interacting with stationary and time-dependent
electromagnetic fields. In the 2D simulations we mimic a Fermi-like interaction
between particles and randomly positioned oscillating clouds. A constant
dawn-dusk electric field and a constant out of plane magnetic field are also
present. The 3D model studies that process in a more realistic configuration: a
modified Harris profile has also been added. Parametric studies have been
performed and the results discussed also in comparison with spacecraft
observations in both the distant and the near-Earth magnetotail.
17:00 H02.10 CLUSTER OBSERVATIONS OF ELECTROSTATIC
ACCELERATION STRUCTURES ABOVE THE POLAR CAP AND IMPLICATIONS FOR THEIR ORIGIN
IN THE MAGNETOPAUSE BOUNDARY LAYER
D. Fontaine, A. Teste, LPP / CNRS, Palaiseau, France
During
quiet periods of Northward IMF, CLUSTER observed electron acceleration structures
at high altitudes along magnetic field lines connected to the polar and
extended along the magnetopause boundary layers. The electrons are observed to
be successively earthward and outward accelerated, forming current sheets of
opposite polarities. The precipitating electrons are accelerated to
keV-energies in relatively stable and broad structures. The outflowing electron
beams, accelerated to weaker energies (tens of eV), form structures at much
smaller scales. These acceleration structures are suggested to result from
electrostatic structures generated at the interface between the magnetopause
boundary layers and the lobes.
17:20 End of the Session
Session Chair: Subra Ananthakrishnan
Session JT
Type Oral Presentation
Schedule Monday, August 15, 13:40-14:40
Room Marmara
13:40 JT.1 EXPLORING THE EPOCH OF REIONIZATION WITH
LOW-FREQUENCY RADIO TELESCOPES
A. R. Parsons, University of California, Berkeley, Berkeley, CA, United States
The
Epoch of Reonization (EoR) represents a major frontier of cosmic evolution yet
to be explored. Redshifted emission from the 21cm hyperfine transition of
neutral hydrogen provides a unique tracer of the primordial intergalactic
medium. But with foregrounds that exceed the expected EoR signal by more than
five orders of magnitude, the level of calibration needed for detecting this
signal is unprecedented in the 100-200MHz band expected to encompass EoR. We
will discuss the various instrumental approaches underway for achieving the
necessary sensitivity and calibration, and discuss plans for second-generation
antenna arrays that might explore EoR tomographically.
14:40 End of the Session
KBE – Non-ionizing Electromagnetic Breast Imaging
Session Chairs: Susan Hagness, Elise Fear
Session KBE
Type Oral Presentation
Schedule Monday, August 15, 13:40-17:00
Room Loft
13:40 KBE.1 TOWARDS A PLANAR MICROWAVE TOMOGRAPHY
SYSTEM FOR EARLY STAGE BREAST CANCER DETECTION
The
advantages of planar Microwave Tomography applied to early stage breast cancer
detection are presented. The breast is compressed between two dielectric plates
in a configuration similar to that of X-ray mammography. This approach would
allow the future implementation of a dual modality imaging system where the
advantages of both techniques can be exploited. The research eff
orts for the development of a planar MT system are described, as well as, the
key features of the latter. A numerical validation is used to show how the
breast compression can lead to an enhancement of the reconstructed images.
14:00 KBE.2 DESIGN OF A MICROWAVE BREAST IMAGING ARRAY
COMPOSED OF DUAL-BAND MINIATURIZED ANTENNAS
We
present a compact dual-band patch antenna array designed for use in a 3-D
microwave tomography system for breast imaging. The array is designed for
operation within the interstitial space of an MRI patient support platform.
This configuration permits scattered-field data acquisition with the breast in
the same position as a benchmark MRI scan, thereby enabling precise
co-registration with breast MRI. We investigate operating characteristics of
the antenna array elements contained in the array using numerical simulations.
We demonstrate that dual-band operation of the array is maintained in the
presence of an ellipsoidal breast phantom.
14:20 KBE.3 MICROWAVE IMAGING FOR BREAST CANCER
DETECTION: COMPARISON OF TOMOGRAPHIC IMAGING ALGORITHMS USING SINGLE-FREQUENCY
AND TIME-DOMAIN DATA
Still
more research groups are promoting microwave imaging as a viable supplement or
substitution to more conventional imaging modalities. A widespread approach for
microwave imaging of the breast is tomographic imaging in which one seeks to
reconstruct the distributions of permittivity and conductivity in the breast.
In this paper two nonlinear tomographic algorithm are compared - one is a
single-frequency algorithm and the other is a time-domain algorithm.
14:40 KBE.4 ONGOING DEVELOPMENT OF MICROWAVE BREAST
IMAGING SYSTEM COMPONENTS
We
present ongoing work at the University of Michigan toward the goal of
developing a microwave inverse scattering system for breast cancer imaging. The
algorithm is built around the Born Iterative Method with a modified cost
function allowing inclusion of a priori information. The calibration is based on
a new formulation for S-parameter measurements. The liquid matching medium is
an oil-water emulsion with high dielectric constant and moderate loss. Last, we
designed a wide-band, linear-phase antenna for both frequency and time-domain
applications. Finally, we present numeric studies of a CW microwave breast
cancer therapy system.
15:00 KBE.5 EFFECTS OF NOISE ON TOMOGRAPHIC BREAST
IMAGING
X. Zeng, A. Fhager, M. Persson, Chalmers University of Technology, Gothenburg, Sweden
Breast
tumor detection using microwaves has attracted considerable interests in the
last few years. Two main approaches for microwave breast imaging are microwave
tomography and radar based imaging. In both approaches, microwave signals are
used to illuminate the breast and scattered signals are received at numerous
locations. The microwave measurements are subject to noise, which may influence
the detection of breast tumor. In this paper, we study the effect of noise on tomographic
breast imaging by numerical simulations. A high contrast breast model is
considered and the image reconstructions are carried out in time domain using a
nonlinear inversion algorithm.
15:20 KBE.6 SAFETY ASSESSMENT OF MICROWAVE BREAST
IMAGING TECHNIQUES: A COMPARISON BETWEEN TWO DIFFERENT APPROACHES
Safety
assessment of ultra-wideband (UWB) microwave breast imaging (MBI) techniques is
examined in this contribution. Specifically, two different approaches have been
applied to evaluate the specific energy absorption (SA) produced by UWB
antennas inside realistic breast models. The adopted power levels and pulse
repetition periods of the tissue sensing adaptive radar (TSAR) system have been
considered to be representative of frequency-swept MBI techniques. Three
different unit voltage UWB pulses have been instead envisaged for MBI systems
directly based on time-domain measurements. Results indicate that the evaluated
SA is below limits prescribed by safety standards.
15:40 Tea/Coffee Break
16:00 KBE.7 FEASIBILITY STUDY OF TUMOR SIZE CLASSIFICATION
VIA CONTRAST-ENHANCED UWB BREAST IMAGING A COMPLEX-DOMAIN ANALYSIS
In
this paper, we study the feasibility of contrast-agent-aided ultra-wideband
(UWB) microwave imaging for breast lesion size classification by studying
received signals in the complex domain. A finite-difference time-domain (FDTD)
numerical phantom is employed to simulate electromagnetic (EM) wave propagation
inside the breast and extract the reflected waveforms with and without
microbubbles in the tumor site. The complex-domain transfer function of
differential response is then used to draw the poles-zero plots (PZPs) and Bode
plots (BPs), which demonstrate the viability of the proposed method for lesion
size categorization.
16:20 KBE.8 IMPROVED CONFOCAL MICROWAVE IMAGING OF THE
BREAST USING PATH-DEPENDENT SIGNAL WEIGHTING
Ultra
Wideband radar is one of the most promising emerging technologies for the
detection of breast cancer. Confocal Microwave Imaging was developed with the
assumption that the breast is dielectrically homogeneous, allowing for the
constructive addition of all returns from tumours within the breast. In a dielectrically
homogeneous breast, each additional signal adds coherently, resulting in an
improved image of tumours present. However, in dielectrically heterogeneous
breasts, not all channels are equal. Therefore, the traditional CMI beamformer
must be redesigned to reward channels with an unobscured view of a particular
voxel within the breast, while also preserving antenna spatial diversity.
16:40 KBE.9 AN EXPERIMENTAL MICROWAVE IMAGING SYSTEM
FOR BREAST TUMOR DETECTION ON LAYERED PHANTOM MODEL
In
this paper, the microwave imaging system currently being developed and realized
at the Scientific and Technological Research Council-BILGEM, is introduced. A
stacked patch antenna has been designed, fabricated and tested in operation in
the experimental setup consisting of a spectrum analyzer (with vector network
analysis option) and a planarly layered breast phantom model with tumor. Images
are successfully obtained by using scattering electromagnetic waves from the
tumor (S11). We were able to detect the elastic tumor model with 2 cm diameter
by using so many frequency and position dependent raw datas.
17:00 End of the Session
J02 – Low Frequency Radio Astronomy II
Session Chairs: Joe Lazio, Yashwant Gupta, Anthony Beasley
Session J02
Type Oral Presentation
Schedule Monday, August 15, 14:40-17:20
Room Marmara
14:40 J02.1 THE LONG WAVELENGTH ARRAY: RESULTS FROM
THE FIRST STATION AND FUTURE PROSPECTS
G. B. Taylor, UNM, Albuquerque, NM, United States
The
Long Wavelength Array (LWA) will be a new multi-purpose radio telescope
operating in the frequency range 10-88 MHz. Scientific programs include
pulsars, supernova remnants, general transient searches, radio recombination
lines, solar and Jupiter bursts, investigations into the "dark ages"
using redshifted hydrogen, and ionospheric phenomena. The first LWA station,
LWA1, has just come-on line demonstrating the success of the LWA design
concept. Additional information about the LWA is online at http://lwa.unm.edu.
Partners in the LWA project include LANL, JPL, NRAO, NRL, UNM, NMT, and
Virginia Tech.
15:00 J02.2 LOFAR: LESSONS FROM ITS DESIGN AND
CONSTRUCTION
LOFAR
is a new radio telescope with 40 stations in the Netherlands and a further 8 in
Germany, France, Sweden and the UK. It operates in the 30-240 MHz frequency
range using unique and innovative techniques, many of which will find their way
in future telescopes such as the SKA. With the construction of LOFAR almost
complete we look back at its design and construction as well as the ongoing
commissioning phase, and draw some conclusions on both successes and
disappointments encountered along the way.
15:20 J02.3 THE EXPANDED VERY LARGE ARRAY LOW BAND
UPGRADE
The
EVLA upgrade will enable full frequency coverage between 1 and 50 GHz. The
legacy 74 and 330 MHz low frequency receivers have been largely decommissioned
by compatibility issues with the new EVLA digital electronics. We describe an
EVLA Low Band initiative to replace the existing narrow band receivers with a
new low-noise, broadband system covering 66 to 470 MHz. The bandwidth at 74 MHz
will increase by more than an order of magnitude while the 330 MHz bandwidth
increases by a factor of 6. The initial deployment of the system will use the
current limited bandwidth feeds.
15:40 Tea/Coffee Break
16:00 J02.4 LOW FREQUENCY APERTURE ARRAY DEVELOPMENTS
FOR PHASE 1 SKA
Aperture
Arrays (AA) mark a new era in radio astronomy combining high sensitivity with a
large field-of-view, enabling very high survey and imaging speeds. This paper
describes the development of low frequency aperture arrays leading up to SKA
phase 1 within the Aperture Array Verification Program (AAVP) as part of the
SKA program.
16:20 J02.5 DEEP LARGE AREA SKY SURVEYS AT METRE
WAVELENGTHS USING GMRT - SOME CHALLENGES
We
have been studying several fields (like ELAIS-N1, GOODS-N/S, AKARI deep field)
and making their deep images at metre wavelengths using the GMRT. We are also
carrying out, TIFR GMRT Sky Survey (TGSS). TGSS is radio continuum survey at
150 MHz, covering about 32000 sq. deg of the sky north of declination of -30
degrees and with typical rms noise of 7 mJy/beam at an angular resolution of
about 20 arcsec. We describe some challenges and ways we tackle them for making
these deep large area sky surveys at metre wavelengths using GMRT.
16:40 J02.6 THE MURCHISON WIDEFIELD ARRAY: A STATUS
REPORT
The
Murchison Widefield Array (MWA) is a low-frequency radio array under
construction in Western Australia by a collaboration of U.S., Australian and
Indian institutions. Science goals require a wide field of view, a large
collecting area, and many antenna elements. The design involves 500 small,
dipole phased arrays ('tiles") with about 10,000 square meters of
aggregate collecting area, and cross-correlation of all pairs. A 32-tile
prototype array is currently in operation at the Murchison Radio Observatory in
the radio-quiet environment of the Western Australian outback. Initial
scientific observations with the prototype are in progress.
17:00 J02.7 A NEW HELIOGRAPH OF THE UTR-2 RADIO
TELESCOPE: DESIGN AND PERFORMANCE
A. A. Koval, A. A. Konovalenko, A. A. Stanislavsky, Institute of Radio Astronomy, Kharkiv, Ukraine
A
new instrument dedicated to observations of the outer corona of the Sun has
been put in operation since 2010. It is based on the antenna system of UTR-2
radio telescope (Institute of Radio Astronomy, Kharkov, Ukraine). This
radioheliograph is capable of producing two-dimensional brightness distribution
images of the solar corona in the frequency range 8 - 33 MHz. At present this
is the only instrument of its kind in the world in the above-mentioned
frequency range for regular observations of the Sun. Included in this report is
a description of the instrument construction and its some features.
17:20 End of the Session
CD – Advanced RF Integrated Circuits
Session Chairs: Nobuyuki Itoh, Shoichi Narahashi
Session CD
Type Oral Presentation
Schedule Monday, August 15, 16:00-17:20
Room Dolmabahçe A
16:00 CD.1 A MICROSTRIP AMPLIFIER DESIGN SUBJECT TO
THE TRANSISTOR PERFORMANCE LIMITATIONS
F. Gunes, S. Demirel, Yýldýz Technical University, Istanbul, TURKEY
This
paper presents synthesis of the microstrip matching circuits to be used at the
input and/or output ports of the low-noise transistor. In this synthesis, input
matching circuit matches the given generator impedance to the optimum noise
impedance of the transistor while the output matching circuit matches the
receiver impedance to the load impedance of the transistor which provides the
available maximum gain within the maximum potential bandwidth at the expense of
the minimum mismatching at the input port. A worked example is given all the
details.
16:20 CD.2 EFFICIENCY IMPROVEMENT OF POWER AMPLIFIERS
WITHOUT DEGRADED LINEARITY USING A NEW TOPOLOGY AND CONTROL METHOD
A. Ronaghzadeh, &. Demir, Middle East Technical University, Ankara, Turkey
This
paper presents a medium-power amplifier design method with two transistors of
the same type in parallel. Using this technique two amplifiers were designed in
class AB at 2.4 GHz. It is demonstrated that by careful selection of the
transistor and dynamically tuning the gate bias of the individual devices and
output matching of the whole amplifier according to input drive level, an
increase of about 40% in PAE is achieved at 7 dB back-off from the P1dB of the
class AB amplifier employing a fixed bias and matching network and giving the
same maximum output power.
16:40 CD.3 DESIGN OF HIGH POWER S-BAND GAN MMIC POWER
AMPLIFIERS FOR WIMAX APPLICATIONS
This
paper reports two different S band GaN MMIC PA designs for WiMAX applications.
First PA has a 42.6 dBm output power with a 55%PAE @ 3.5 GHz and 16 dB small
signal gain in the 3.2-3.8 GHz frequency range. When two of these MMICs were
combined by using off-chip Lange Couplers, 45.3 dBm output power with a 45%PAE
@3.5Ghz and 16 dB small signal gain were obtained with less than 0.2 dB gain
ripple in the 3.3-3.8 GHz frequency range.
17:00 CD.4 ON FURTHER DISCUSSION OF BARKHAUSEN
CRITERION
It
has been pointed out that Barkhausen criterion cannot be used as a general
oscillation condition, to evaluate (1) growth of oscillation, (2) steady state
amplitude of oscillation in terms of circuit and active device parameters and
(3) to as certain amplitude and frequency stability of oscillation, (4) to
audit the nature of oscillation whether it is soft-self or hard-self excited.
Here it has been shown that all these limitations can be over come through
clubbing of quasi-state and quasi-linearization techniques and modified
Barkhausen criterion can also be applied to four terminal and two terminal
oscillators.
17:20 End of the Session
Session Chair: P. Tavella
Session A03
Type Oral Presentation
Schedule Tuesday, August 16, 08:00-12:00
Room Dolmabahçe C
F. Arias, G. Panfilo, G. Petit, BIPM, Sevres, France
This
article presents how timescales are established and maintained at the
International Bureau of Weights and Measures (BIPM), on the basis of
international cooperation. We describe the characteristics of International
Atomic Time (TAI) and Coordinated Universal Time (UTC) and the main features of
the methods used for their calculation.
08:20 A03.2 THE ROLE OF THE ITU-R IN TIME SCALE
DEFINITION
R. L. Beard, U.S. Naval Research Laboratory, Washington,D.C., United States
The
ITU is the leading United Nations agency for Radio and Telecommunications
coordination worldwide. Frequency spectrum utilization is managed through Radio
Conferences and Study Groups. An important aspect of spectrum utilization is
the underlying coordination established by the broadcast international time
scale used throughout the world. This international time scale is Coordinated
Universal Time (UTC) defined by the International Telecommunication Union
(ITU-R) as a stepped atomic time scale enabling UT1 to be recovered from UTC.
Todays systems utilize continuous timing consequently deliberations have been
ongoing within the ITU-R on modifying UTC to be a continuous time scale.
08:40 A03.3 OVERVIEW OF JAPAN STANDARD TIME GENERATION
National
Institute of Information and Communications Technology (NICT) generates and
supplies Japan Standard Time (JST). JST is made from an average atomic time
which is calculated by using 18 commercial Cs atomic clocks. In this
calculation, there are some original methods in estimating clock rate and clock
weighting. The actual signal of JST is generated by realization of this average
atomic time. In this process, frequency control method was optimized recently
and frequency stability of JST has been largely improved.
09:00 A03.4 MERGING MASER AND CESUIM CLOCKS IN
TIMESCALES
D. Matsakis, US Naval Observatory, Washington, DC, United States; G. Panfilo, BIPM, Paris, France
A
variety of ways exist to combine clocks with different characteristics in a
timescale. A Kalman Filter could assign different phase, frequency, and
frequency drift process noises to the different clock types. In this paper we
use an ensemble of cesium and maser clocks to construct a timescale that is
based upon an average of masers that are detrended against a cesium-only
frequency scale, and also one which is based upon an average of masers being
steered to the cesium timescale. Different ensemble algorithms will be
compared.
09:20 Tea/Coffee Break
09:40 A03.5 REAL-TIME GENERATION OF THE SIM TIME SCALE
(SIMT) FROM INTERNATIONAL CLOCK COMPARISONS
The
Sistema Interamericano de Metrologia (SIM) is one of the worlds five major
regional metrology organizations (RMOs). It includes the national metrology
institutes (NMIs) of the 34 nations of the Organization of American States
(OAS). The SIM time network (SIMTN) continuously compares the time standards of
SIM NMIs and produce measurement results in real-time by utilizing the Internet
and the Global Positioning System (GPS). The SIMTN data are used for the
real-time generation of an international time scale called SIMT. This paper
provides a brief overview of the SIMTN and the SIMT.
10:00 A03.6 CURRENT STATUS OF THE FRENCH ATOMIC TIME
SCALES TA(F) AND UTC(OP)
P. Uhrich, M. Abgrall, D. Valat, LNE-SYRTE, Observatoire de Paris, Paris, France
Two
atomic time scales are currently generated by LNE-SYRTE: the French Atomic Time
TA(F) and UTC(OP). TA(F) has been recently improved by the steering on Primary
Frequency Standards, remaining close to the SI second within 1.8 x 10-15. A new
UTC(OP) will be based on one Hydrogen Maser, steered on an ensemble clock, in
addition to a steering on the laboratory PFS. First operational results are
showing that staying within 30 ns from UTC should be feasible.
10:20 A03.7 ALGORITHM AND PRELIMINARY OBSERVATIONS OF
NEW TIME SCALE OF NPLI
P. P. Thorat, P. Banerjee, National physical Laboratory, New Delhi, India
National
Physical Laboratory, New Delhi (NPLI) has been maintaining time scale UTC
(NPLI) with only one cesium atomic clock. NPLI has recently developed an
automatic intercomparison system for the development of better time scale
combining all its five clocks. A new algorithm has also been developed for this
purpose. Using this algorithm, the analysis has been done based on the
preliminary measurement data. Algorithm seems to produce encouraging results.
This paper elaborates the algorithm and presents the analytical observations
10:40 A03.8 TIMING IN TELECOMMUNICATIONS NETWORKS
J. Levine, National Institute of Standards and Technology, Boulder, Colorado, United States
I
describe the statistical considerations used to design systems whose clocks are
compared using dial-up telephone lines or the Internet. The comparison is
usually used to synchronize the time of a client system to the time of a server
or to a national time scale. The design includes a dynamic estimate of the
system performance and a comparison between the performance and the required
stability based on external considerations. The algorithm adjusts the
parameters of the algorithm to realize the specified performance at minimal
cost, where the cost is proportional to the inverse of the polling interval.
11:00 A03.9 THE NEW TIME AND FREQUENCY LABORATORY FOR
THE SARDINIA RADIO TELESCOPE
A
time laboratory was established at the Astronomical Observatory of Cagliari
more than one century ago, aimed for time-tagging scientific observations. At
present, this laboratory is facing up a deep refurbishment in order to cope with
the much tighter specifications on phase noise, time resolution, and frequency
stability required by the new scientific applications planned for the Sardinia
Radio Telescope. As a result of the participation to millimeter Very Long
Baseline Interferometry and pulsar timing experiments of SRT, the new Time and
Frequency laboratory will be called to provide extremely low phase noise and
highly stable frequency references.
11:20 A03.10 A DIGITAL TIME SCALE AT THE NATIONAL INSTITUTE
OF STANDARDS AND TECHNOLOGY
S. Romisch, S. R. Jefferts, T. E. Parker, NIST, Boulder, CO, United States
An
integrated time scale has as primary data a unit of duration (time interval)
defined by atomic standards according to the definition of the SI second. The
availability of more than one atomic standard allows for averaging, thereby
improving the performance of the time scale with respect to each of the atomic
standards (clocks). The measurement of time differences between the different
clocks is at the core of a time scale. A novel approach to the measurement of
time differences has been developed at NIST and will be compared with the
present commercial state-of-the-art.
11:40 A03.11 SATELLITE CLOCKS CHARACTERIZATION AND
MONITORING FOR GLOBAL NAVIGATION SATELLITE SYSTEMS
In
Global Navigation Satellite Systems (GNSS) the users position is determined
measuring the time of flight of the signals broadcast from satellites and
therefore it is fundamental to have precise and stable atomic clocks on board.
The clock behaviour has hence to be continuously monitored and any
malfunctioning has to be detected immediately to ensure the adequacy to the
positioning service. This paper will describe the main methodologies for
validation of on board clocks and their implementation in a robust software
used at INRIM in the framework of the European project Galileo.
12:00 End of the Session
B03 – Hybrid Methods (in memory of Robert G. Kouyoumjian)
Session Chairs: Prabhakar Pathak, Giuliano Manara
Session B03
Type Oral Presentation
Schedule Tuesday, August 16, 08:00-12:00
Room Anadolu Auditorium
08:00 B03.1 THE CONTRIBUTION OF PROF. ROBERT
KOUYOUMJIAN TO EDGE DIFFRACTION AND FIELD TRANSITION AT AND NEAR SHADOW
BOUNDARIES USING UTD
The
development of the Kouyoumjian & Pathak UTD diffraction coefficient will be
summarized. Applications of the UTD on basic and complex structures (from
ground planes to airframes), based on my own personal experience, will be
presented and the impact of the K & P UTD diffractions coefficient will be
highlighted.
08:20 B03.2 A UNIFORM GEOMETRICAL THEORY OF
DIFFRACTION (UTD) FOR CURVED EDGES ILLUMINATED BY ELECTROMAGNETIC BEAMS
A
UTD is presented for an arbitrary curved perfectly conducting wedge when it is
illuminated by an electromagnetic (EM) complex source beam or even an
astigmatic Gaussian beam. The UTD solution is developed from a generalization
of the asymptotic high frequency solutions to appropriate canonical problems
involving the diffraction of complex source beams by a straight wedge with
planar faces that are perfect electrical conductors (PECs). Here, one cannot
simply assume, apriori, the use of analytic continuation of the well known UTD
for curved edges given previously for real sources to directly furnish the
result for complex sources (beams).
08:40 B03.3 THE JOY OF UNDERSTANDING RAY TECHNIQUES
AND UNIFORM THEORIES IN EM SCATTERING: I OBSERVED THE KELLERS CONE AT A HOTEL!
Y. Rahmat-Samii, University of California Los Angeles (UCLA), LosAngeles, United States
It
is with utmost gratitude that I present this invited paper at this 2011 General
Assembly session dedicated to the memory and professional life of Prof.
Kouyoumjian. He touched the technical life of almost everyone who dealt with
the high frequency diffraction techniques. His work on UTD has secured his
position as one our most celebrated researcher in our community. In this
presentation I would like to re-visit Kellers diffraction theory and various
uniform theories. Additionally, I would like to share an interesting recent
experience on the observation of Kellers cone.
09:00 B03.4 A SURVEY ON THE EXTENSION OF THE UTD TO
THE ANALYSIS OF INHOMOGENEOUS PLANE WAVE DIFFRACTION
G. Manara, P. Nepa, University of Pisa, Pisa, Italy
The
extension of the Uniform Geometrical Theory of Diffraction (UTD) to the
analysis of inhomogeneous plane wave diffraction is reviewed. The
two-dimensional solution for the scattering of inhomogeneous plane waves by a
perfectly conducting wedge in a lossless medium is introduced. This solution is
then extended to account for dissipative losses in the medium surrounding the
wedge, as well as non perfectly conducting wedges. Suitable expressions for the
fields are also found in the more general three-dimensional case, for arbitrary
polarization. Finally, suitable UTD expressions for calculating electromagnetic
scattering from polygonal cylinders buried in lossy media are provided.
09:20 Tea/Coffee Break
09:40 B03.5 CONVERGENCE OF A FULLY OVERLAPPING DOMAIN
DECOMPOSITION METHOD
T. Peng, K. Sertel, J. L. Volakis, ElectroScience Laboratory, Columbus, OH, United States
A
fully overlapping domain decomposition method (DDM) is proposed for finite
element modeling of small features within large domains. The approach decouples
the fine mesh associated with antenna details from that of the background
domain. This allows for unstructured meshing, providing great flexibility in
designing in situ antennas. Another advantage of this algorithm is its faster
convergence as compared to traditional non-overlapping domain decomposition
methods of the same order. This is due to the smaller iteration matrix
eigenspectrum. In this paper, the accuracy of the fully overlapping domain
decomposition method is presented with h-refinement analysis.
10:00 B03.6 RECENT ADVANCES IN THE INCREMENTAL THEORY
OF DIFFRACTION FOR COMPLEX SOURCE POINT ILLUMINATION
We
discuss some recent advances in the incremental formulation for the field
diffracted by edges in perfect electric conductor (PEC) objects illuminated by
a CSP expansion, with application to the analysis of large reflectors. A
significant augmentation of the CSP PO estimate is achieved by including along
the structure's edges both a line integration of an incremental fringe field
and an incremental double-diffraction field. The addition of these incremental
field terms provides the correct estimation of the radiated field.
10:20 B03.7 HYBRID METHODS BASED ON GENERALIZED
SCATTERING MATRICES
E. Martini, C. Della Giovampaola, A. Toccafondi, S. Maci, University of Siena, Siena, Italy
A
general hybrid technique based on generalized scattering matrices is presented.
The analysis domain is decomposed into separate subdomains, which are
independently studied and characterized by a generalized scattering matrix,
where ports are associated with a set of wave objects. The interactions among
subdomains are described by proper subdomain connections. Two particular
implementations are illustrated, where wave objects are complex point source
beams (CPS) and spherical waves, respectively. The first choice leads to an
efficient numerical procedure due to the angular selectivity of the CPS beams,
the second one has the advantage of direct interfaceability with spherical
near-field measurements
10:40 B03.8 NUMERICAL COMPUTATION OF CORNER
DIFFRACTION COEFFICIENTS FOR A PLANE ANGULAR SECTOR
A. K. Ozturk, ASELSAN Inc., Ankara, Turkey; R. Paknys, Concordia University, Montreal, QC, Canada
Numerical
diffraction coefficients are derived for vertex-diffracted currents on a
semi-infinite plane angular sector. The currents are defined as the difference
between the exact and PTD currents. The difference current is formulated as a
wave traveling away from the vertex with unknown amplitude and decay factors. The
unknown factors are calculated by using least squares fit. The discontinuities
of the current density along the shadow boundaries are removed by the
vertex-diffracted currents. It is also demonstrated that vertex-diffracted
currents provide a remarkable improvement in the accuracy of the RCS pattern in
the low level regions.
11:00 B03.9 LAST PHD SUPERVISED BY PROFESSOR
KOUYOUMJIAN: EXTENDED UTD BY DR. BUYUKDURA
A. Altintas, Bilkent University, Ankara, Turkey
While
he is a Professor Emeritus at Ohio State, Professor Kouyoumjian supervised a
thesis work by Merih Buyukdura. They first derived a dyadic Greens function for
a PEC wedge using spherical wave functions and employed asymptotic approximation.
They also derived the extended UTD in which higher order terms in the
diffraction matrix are predicted. The thesis was defended in 1984. In this
presentation, a brief discussion of edge waves as derived from the asymptotic
expansion of dyadic Greens function in terms of spherical functions will be
made and afterwards the derivation of extended UTD diffraction coefficients
will be given.
11:20 B03.10 EXACT RADIATION BY A LINE SOURCE LOCATED
INSIDE A CONFOCAL ELLIPTIC LAYER OF DNG METAMATERIAL
The
two-dimensional problem of radiation from a line source encased inside an
elliptic-cylinder confocal sheath of DNG metamaterial is solved exactly by
separation of variables, utilizing series expansions of Mathieu functions. The
radiation pattern is studied as a function of frequency, location of the line
source along the major axis of the elliptical cavity, and thickness of the
confocal sheath. A comparison of the exact solution with the geometrical optics
solution of the problem is performed.
11:40 B03.11 A STOCHASTIC EXTENSION OF THE UNIFORM
THEORY OF DIFFRACTION ACCOUNTING FOR GEOMETRICAL UNCERTAINTY OR SURFACE AND
EDGE ROUGHNESS
F. Puggelli, G. Carluccio, G. Minatti, M. Albani, University of Siena, Siena, Italy
We
present a stochastic extension of the Uniform Theory of Diffraction (UTD) which
is capable to account for some uncertainty in the objects position or geometry,
including roughness of surfaces or edges. Namely, we derive a solution for the
electromagnetic field scattered by a perfectly conducting wedge whose faces are
described as a statistical perturbation of a standard flat wedge. We give a
uniform closed form expressions for the evaluation of the main statistical
moments of the total electric field. The proposed statistical UTD formulation
is suitable for engineering applications which involve UTD ray based codes.
12:00 End of the Session
CB – Antenna Channel Interactions for Future Wireless Communications
Session Chairs: Buon Kiong Lau, Koichi Ogawa
Session CB
Type Oral Presentation
Schedule Tuesday, August 16, 08:00-10:20
Room Dolmabahçe A
08:00 CB.1 DESIGN OF WIDE ANGLE REFLECTION
REFLECTARRAY USING MULTI-LAYER MUSHROOM STRUCTURE TO IMPROVE PROPAGATION
T. Maruyama, K. Furuno, Y. Oda, J. Shen, N. Tran, H. Kayama, NTT DOCOMO, INC., Kanagawa, Japan
This
paper proposes a multi-layer mushroom reflectarray to achieve a wide angle of
reflection (AOR) reflectarray at a super high frequency that can be used to
improve the Multiple-In-Multiple-Out capacity in a line-of-sight environment.
The paper also presents a detailed design chart to satisfy the desired AOR by
applying LC resonant circuit theory. A 70 degree-AOR reflectarray at 11 GHz is
designed and the proposed reflectarray exhibits good performance based on
Finite Element Method calculations.
08:20 CB.2 PRACTICAL MULTI-ANTENNA TERMINALS IN LTE
SYSTEM PERFORMANCE SIMULATIONS
F. Athley, L. Manholm, J. Friden, A. Stjernman, Ericsson AB, Gothenburg, Sweden
In
cellular radio network simulations the modeling of terminal antennas is often
extremely simplified. In this paper the impact of using realistic terminal
antennas in LTE system simulations is investigated. Simulation results using
measured radiation patterns of a number of typical multi-antenna terminals are
compared with results using an ideal antenna model. The results show that the
impact is weak in a scenario with high intercell interference while a
substantial performance degradation can be observed in a scenario with low
interference. An analysis of relations between antenna properties and system
performance is also presented.
08:40 CB.3 EFFECTS OF HANDS ON THE 4-BRANCH MRC
DIVERSITY GAIN FOR TERRESTRIAL DIGITAL BROADCASTING PORTABLE TV
K. Ogawa, K. Honda, Toyama University, Toyama, Japan
This
paper studies on effects of hands on the diversity gain for a 4-branch MRC
implemented in terrestrial digital broadcasting TV. Firstly, using a
four-element dipole array, the relationship between decrease in the diversity
gain and reduction of the receive power, and decrease in the diversity gain and
the number of branches to be reduced received power, was investigated. Then, a
simple method of predicting the diversity gain under the power imbalance
condition is given. Finally, the proposed method is confirmed by the analysis
using a model of a portable digital broadcasting TV set held with both hands.
09:00 CB.4 ANGLE AND POLARIZATION DIVERSITY IN
COMPACT DUAL-ANTENNA TERMINALS WITH CHASSIS EXCITATION
For
multiple antennas on a compact terminal chassis, chassis current excitation can
severely increase mutual coupling between the antennas. This is because the
same characteristic mode of the chassis may be strongly excited by more than
one antenna. Here, we propose to use one antenna that exploits chassis
excitation and introduce a second antenna that minimizes chassis excitation. In
this way, angle and polarization diversity can be realized. The concept is
illustrated and verified through the design of a practical dual-antenna
prototype at 920 MHz, which achieves an isolation of over 30 dB and total
efficiencies of above 80%.
09:20 Tea/Coffee Break
09:40 CB.5 MULTI-ANTENNA DECOUPLING TECHNIQUE EXPLOITING
MISO CHANNEL ON NEIGHBORING ANTENNAS
In
this paper, a novel decoupling technique suitable for a compact array antenna
is proposed. In this technique, an orthogonal excitation weight in MISO channel
between 2x1 antennas are utilized. The simulation results demonstrate the
excellent isolation and matching characteristics can be obtained when the proposed
decoupling technique is applied to a compact three inverted-F array. Also, the
proposed technique offers high radiation efficiency over the broad bandwidth.
10:00 CB.6 DESIGN OF COMPACT SINGLE-SECTION
DIRECTIONAL COUPLER FOR BUTLER MATRIX BEAM-FORMING MIMO
This paper demonstrates a new design of 3-dB coupler
operating between 3.1 GHz and 10.6 GHz. Together with UWB phase shifter, this
coupler is claimed to be one of the key factors in designing a Butler Matrix
for a beamforming network. The arrangement between beamforming and
multiple-input and multiple-output (MIMO) can broaden the coverage and capacity
of users for wireless communication system. The proposed coupler design was
accomplished in multilayer microstrip-slot technology by employing broadside
coupling technique which offers a very tight coupling of 3 dB over the
designated frequency band.
10:20 End of the Session
Session Chairs: Alphan Sennaroglu, U. Morgner
Session D03
Type Oral Presentation
Schedule Tuesday, August 16, 08:00-12:00
Room Dolmabahçe B
08:00 D03.1 GENERATION OF FEW-OPTICAL-CYCLE PULSES
TUNABLE FROM THE NEAR TO THE FAR IR BY OPTICAL PARAMETRIC AMPLIFIERS
We
exploit different optical parametric amplification schemes to generate
ultra-broadband pulses with J-level energy broadly tunable from the near to the
far-IR spectral region. In all cases we approach the single optical cycle limit
with suitable compression techniques. Such pulses enable ultrafast spectroscopy
on a variety of systems with unprecedented temporal resolution.
08:20 D03.2 NONLINEARITY ENGINEERING OF MODE-LOCKED
FIBER LASERS: SIMILARITON AND SOLITON- SIMILARITON LASERS
F. O. Ilday, B. Oktem, C. Ulgudur, Bilkent University, Ankara, Turkey
Fiber
lasers are attractive with their simplicity, high powers and low cost. However,
propagation of short pulses in optical fiber leads to nonlinear effects, which
limit the technical performance. These effects drive rich dynamics, which is
interesting from a fundamental perspective. The nonlinear waves community has
unraveled the fascinating world of solitons and similaritons through experiments
in fibers. This paper overviews the recent development of the
soliton-similariton laser. The original similariton laser was the first to work
with nonlinear effects, rather than minimizing or compensating them. In the
soliton-similariton laser, the propagation is strongly nonlinear everywhere.
08:40 D03.3 FEMTOSECOND SOURCES FOR OPTICAL ARBITRARY
WAVEFORM GENERATION
Advances
in high repetition-rate femtosecond laser technology for optical arbitrary
waveform generation will be described. Combs spanning two octaves, from 500nm
to 2mm, based on GHz modelocked Ti:sapphire and
erbium-fiber lasers, have been carrier-envelope stabilized and frequency
referenced.
09:00 D03.4 RECENT PROGRESS IN CARBON NANOTUBE SATURABLE
ABSORBERS FOR ULTRAFAST BULK SOLID-STATE LASERS
F. Rotermund, Ajou University, Suwon, Republic of Korea, South Korea
Carbon
nanotubes are one of the most investigated nanomaterials due to their unique
electric and optical properties. In recent years, the nonlinear optical
characteristics were intensively investigated not only for electronic, but also
for photonic applications. In this work, recent progress in novel saturable
absorbers based on single-walled carbon nanotubes (SWCNTs) applicable for
passive mode-locking of ultrafast bulk solid-state lasers is reviewed.
Important linear and nonlinear optical characteristics of SWCNT saturable
absorbers and their application as ultrafast mode-locking devices for different
bulk lasers in the spectral range between 800 and 2000 nm will be shown.
09:20 Tea/Coffee Break
09:40 D03.5 ASYNCHRONOUS OPTICAL SAMPLING WITH GHZ
REPETITION RATE FEMTOSECOND LASERS FOR HIGH PRECISION TERAHERTZ SPECTROSCOPY
T. Dekorsy, G. Klatt, R. Gebs, C. Janke, A. Barteks, University Konstanz, Konstanz, Germany
We
report a terahertz time-domain spectrometer with 6THz spectral coverage and
1GHz resolution based on high-speed asynchronous optical sampling (ASOPS).
ASOPS employs two femtosecond lasers with 1GHz repetition rate which are
stabilized to a repetition rate off-set frequency of 2kHz. The time delay
between pump pulses exciting a photoconductive THz emitter and probe pulses is
scanned without a mechanical delay stage. The timing jitter between pump and
probe pulses is reduced to 40fs over the full scan range. We demonstrate the
capabilities of ASOPS for gas spectroscopy and the characterization of
frequency selective surfaces.
10:00 D03.6 ULTRASHORT PULSE AMPLIFICATION IN FIBERS:
CHALLENGES, STATUS AND POTENTIAL
J. Limpert, Friedrich Schiller University Jena, Jena, Germany
The
recent demonstration of rare-earth-doped fiber lasers with a continuous-wave
output power approaching the 10 kW-level with diffraction-limited beam quality
has proven that fiber lasers constitute a power-scalable solid-state laser
concept. To generate intense pulses from a fiber several fundamental limitations
have to be overcome. Nevertheless, novel experimental strategies and fiber
designs offer an enormous potential towards ultrafast laser systems with high
average powers (>kW) and high peak power (>GW). The challenges,
achievements and perspectives of ultrashort pulse generation and amplification
in fibers will be reviewed.
10:20 D03.7 FEMTOSECOND NON-DIFFRACTING BESSEL BEAMS
AND CONTROLLED NANOSCALE ABLATION
J. M. Dudley, FEMTO-ST, Besancon, France
We
review our recent results applying the stable nonlinear propagation of
nondiffracting Bessel beams to femtosecond laser ablation in dielectric
materials. We describe our spatial light modulator setup that allows for
flexible and reconfigurable beam profile synthesis, we interpret the physics in
terms of the formation of a steady plasma channel, and we present results of
both multishot and single shot machining.
10:40 D03.8 TRIPLE PHOTONS : FROM NONLINEAR GENERATION
TO QUANTUM CORRELATIONS
We
implemented an experiment using a KTP crystal pumped at 532 nm that allowed the
first generation of triple photons. It corresponds to the creation of three
correlated photons from the splitting of a single photon from a pure third
order down conversion parametric process. We gave prominence to the experimental
and theoretical demonstrations of quantum correlations of these triple photons.
We considered several protocols, including the recombination of the three
photons and the three possible recombinations by pairs. These original results
open the way to new fundamental quantum optics studies that should have
applications in quantum information and cryptography.
11:00 D03.9 OPTICAL PHENOMENA AND DYNAMICS IN ORGANIC
MICROCAVITY LASER
Formalism
for the interaction of organic molecules with a microstructure cavity is
presented. We study the effect of emission and absorption properties of organic
molecules in a micro-structured cavity on lasing condition. The formalism is
based on coupled-mode theory and provides analytical expression for steady
state operation. This study suggests routes to obtain an ultra-low threshold
organic laser that can ultimately pave the way to development of an
electro-luminescent solid-state organic laser device.
11:20 D03.10 A TABLETOP MID-IR LIGHT SOURCE FOR THE
GENERATION OF SUB-1-NM COHERENT ULTRAFAST X-RAYS
We
demonstrate a compact 20-Hz-repetition-rate mid-IR OPCPA system operating at
the central wavelength of 3900 nm with an FWHM bandwidth of 600 nm and
delivering 8-mJ pulses that are compressed to 83 fs (< 7 optical cycles).
Because of the long optical period (~13 fs) and a high peak power, the system
opens a range of unprecedented opportunities for tabletop ultrafast science and
is particularly attractive as a driver for a highly efficient generation of
ultrafast coherent X ray continua for bio-molecular and element-specific
imaging. In a preliminary experiment, we extend the spectral region of a fully
phase-matched higher order harmonic generation to 1.6 keV which provides a
significant photon flux inside and beyond the X-ray water window, including the
fingerprint region of magnetic Ledges. This is the most extreme documented
nonlinear frequency conversion corresponding to the harmonic order of >5000
and the broadest continuum reported to date for any laser source.
11:40 D03.11 CARBON NANOTUBES BASED PHOTONICS: TOWARDS
THE LASER
Semiconducting
single wall carbon nanotubes (s-SWNTs) have generated a growing interest for
several years due to their extraordinary optical properties. A strong
enhancement of the photoluminescence properties has been obtained thanks to the
extraction of s-SWNTs. These advances led to the first demonstration of optical
gain in carbon nanotubes and are a precursor to obtain nanotube-based laser.
Finally, we will present the integration of s-SWNT in silicon photonic
structures, and experimentally demonstrate light emission in silicon
waveguides. These results constitute a significant milestone towards the
development of carbon nanotube based laser sources in silicon.
12:00 End of the Session
E03 – High Power and Intentional EMI (in memory of Carl E. Baum)
Session Chairs: Frank Sabath, Karl Langenberg, William Radasky
Session E03
Type Oral Presentation
Schedule Tuesday, August 16, 08:00-12:00
Room Galata
08:00 E03.1 REMEMBERING CARL E. BAUM - TRIBUTE TO A
DISTINGUISHED SCIENTIST
This
contribution is a tribute to a completed career that has spanned more than four
decades. Dr. Carl E. Baum was a remarkably creative engineer who has introduced
innumerable new concepts in mathematics, electromagnetic theory, and system
design, many of which remain the standards of excellence today. From his
earliest designs in electromagnetic pulse (EMP) sensors and simulators to the
latest developments in high-power microwave and ultra- wideband antenna and
system design, his research has remained ever on the forefront of technology.
08:20 E03.2 ELECTROMAGNETIC DETECTION IN NATURAL AND
MAN-MADE DISASTERS
Previously
the authors developed a theory for detecting objects through a complex
dielectric interface using the mathematical structure of the dyadic Green's
function to improve upon existing approximations for predicting the
electromagnetic fields generated by and onto canonical structures such as loops
and dipoles. By restructuring the dyadic Green's function formalism we have
derived simple expressions for scattering objects embedded in the same complex
dielectric as the sensor, as well as objects at the dielectric interface and
those outside the sensor dielectric region. Examples are given for detection
over a conducting surface and for an embedded object.
08:40 E03.3 ENERGY PATTERNS OF THE PROTOTYPE
IMPULSE-RADIATING ANTENNA
In
this paper we consider a reflector-type of an Impulse Radiating Antenna (IRA)
as an example of a hyperband antenna. The radiation pattern of an IRA is a
strong function of frequency. The lower frequencies of the input pulse have
lower gain and large beam-widths, while the higher frequencies have a higher
gain and smaller beam-widths. We describe an energy pattern of the IRA, as a
simple and unique descriptor of the transient antenna.
09:00 E03.4 DESIGN AND SIMULATION OF A COAXIAL
EXPONENTIAL TRANSMISSION LINE FOR A HALF IMPULSE RADIATING ANTENNA
This
paper describes the simulation and design of a coaxial exponential matching
transmission line for the connection of a 50-Ohm generator to a Half Impulse
Radiating Antenna (HIRA) having an input impedance Za= 100 Ohm. The frequency
band of adaptation is defined between 50 MHz and 1 GHz. The principles of
design and the simulation of the performance of the adaptor in time and
frequency domain are presented and discussed.
09:20 Tea/Coffee Break
09:40 E03.5 GENERATION AND RADIATION OF HIGH-POWER
MESOBAND WAVEFORMS USING QUARTER-WAVE SWITCHED OSCILLATORS
In
the late 1990s and early 2000s, Carl Baum proposed the idea of generating
moderate bandwidth electromagnetic waveforms using quarter-wave switched
oscillators. After his initial conceptual proposition, it took several years to
realize these systems, and many lessons were learned along the way. This
article captures the details of the modeling and design methodologies that we
have developed over the years in order to obtain oscillators with specific
characteristics. The design methodology consists of a delicate balance among
the pulsed power, electrodynamic, and mechanical considerations, each of which
often work against each other in practice.
10:00 E03.6 A SWITCHED OSCILLATOR AS AN ANTENNA FOR
HIGH POWER THZ GENERATION
This
paper presents an approach to high power THz generation that uses a Switched
Oscillator (SwO) as a photoconductively-switched antenna. A simplified model is
used to demonstrate the SwO as an effective THz radiator. Numerical simulations
are used to optimize various parameters of interest with the primary objective
of maximizing the radiated energy and minimizing lossess. The radiation Q and
resonant frequency are obtained as function of each parameter.
10:20 E03.7 USING THE HALF FOURIER TRANSFORM FOR SEM
ANALYSIS OF BOTH EARLY AND LATE TIME RESPONSES IN THE PRESENCE OF NOISE
A
technique for estimating the SEM parameters of damped sinusoids utilizing both
early and late time transient scattering data contaminated by noise is
described using the Half Fourier Transform (HFT). The importance of this novel
methodology is how to simultaneously exploit both early time and late time data
as for a practical system it is difficult to separate them and still be able to
identify the late time poles along with the early time specular type of
returns.
10:40 E03.8 STATISTICAL DESCRIPTION OF SHIELDING
PROBLEMS USING MULTIPOLE ANALYSIS
K. Koerber, L. Klinkenbusch, University of Kiel, Kiel, Germany
The
paper describes the influence of small statistical variations in the physical
parameters on the shielding behavior of an enclosure. The varying parameters
are given in terms of the first few statistical moments of their distributions.
From these the amplitudes of a spherical-multipole expansion are derived
analytically. These multipole amplitudes contain the statistical properties of
the electromagnetic field valid not only in a single point but in a spherical
region around the center of the expansion inside of a shield. Two first
examples demonstrate the validity of the approach.
11:00 E03.9 WHAT CAN BE LEARNED FROM DOCUMENTED
INTENTIONAL ELECTROMAGNETIC INTERFERENCE (IEMI) ATTACKS?
F. Sabath, Federal Ministry of Defence, Bonn, Germany
The
existing threat by criminal (intentional) use of electromagnetic tools is
investigated. Reported Intentional Electromagnetic Interference (IEMI) attacks
and similar incidents will be analyzed and discussed in regard to aspects like
motivation and technical skills of the culprits, characteristics of the
generated IEMI environment as well as effects on the target systems. Concluding
common characteristics will lead to a discussion of the technological challenge
of recognition and identification of an IEMI attack as well as backtracking of
observed malfunction and destructions to an external IEMI environment.
11:20 E03.10 COMBINATION OF THE FAILURE PROBABILITY
WITH A RANDOM ANGLE OF INCIDENCE OF THE RADIATED INTERFERENCE
Electronic
devices exposed to high level electromagnetic interference will fail with a
certain probability. Knowing this failure probability is essential when a
system is being designed to withstand intentional electromagnetic interference
(IEMI). In previous investigations failure probability was analyzed for the
case where a device was illuminated from one direction only. If the device is
illuminated from other directions, then the failure probability will change. In
this contribution it is discussed how the failure probability determined for
one direction can be extended in order to include a random angle of incidence
of the interference.
11:40 E03.11 AUTOMATED AND ADAPTIVE RF EFFECTS TESTING
Testing
electronics for vulnerability to radio frequency (RF) radiation is
time-consuming, due to the large number of source variables of interest,
including center frequency, pulse width, pulse repetition frequency, number of
pulses, and bandwidth. One must intelligently select the source parameters most
likely to expose the greatest vulnerability. We do so here using standard
techniques from minimization theory. Within a space of two or more variables,
we search for the combination that upsets the system at the lowest power or
field level. We investigated the vulnerability of media converters to pulsed RF
fields, by pinging a remote computer.
12:00 End of the Session
F03 – Tropospheric Modeling for Radiowave Propagation and Radar Remote Sensing
Session Chairs: Robert Watson, Marlene Pontes
Session F03
Type Oral Presentation
Schedule Tuesday, August 16, 08:00-12:00
Room Haliç
08:00 F03.1 COMPARISON OF RADAR REFLECTIVITY
CALCULATIONS TO SATELLITE MEASUREMENTS ACROSS THE MELTING LAYER OF PRECIPITATION
Calculations
of the radar reflectivity factor across the melting layer of precipitation,
based on the eccentric spheres model for melting ice particles, successfully
reproduce measured data provided by the Precipitation Radar (PR) of the
Tropical Rainfall Measurement Mission (TRMM) satellite. Our model follows TRMM
measurements best if the raindrops beneath the melting layer are sized
according to the Marshall-Palmer distribution and the rain rate is low. The
Gamma size distribution is more appropriate for high rain rates. The
comparisons bring to the light cases of incorrect information about the height
and width of the melting layer in TRMM data.
08:20 F03.2 FADE DURATION AND FADE SLOPE STATISTICS
DERIVED FROM LONG-TERM ANIK-F2 SATELLITE BEACON MEASUREMENTS IN OTTAWA-CANADA
C. Amaya, T. Nguyen, Communications Research Centre Canada, Ottawa, Ontario, Canada
Fade
duration and fade slope provide essential information to design fade mitigation
techniques. Statistics for 2006-2009 from the 20-GHz beacon of Telesats Anik F2
satellite are presented. The impact of data filtering is discussed. Four fade
duration models are tested using Anik F2 distributions. Slope PDFs show
symmetry between positive and negative values; a clear dependence on fade level
is verified. General agreement was observed between measured CDFs and the ITU-R
model. Finally, the comparison of distributions from the 20- and 30-GHz beacons
of NASA ACTS satellite confirms the frequency-independent behaviour of fade
slope.
08:40 F03.3 STUDIES ON RAIN STRUCTURE BASED ON GROUND
BASED DROPSIZE DISTRIBUTION AND RAIN ATTENUATION MEASUREMENTS OVER AN EARTH
SPACE PATH
A. Bhattacharya, A. Maitra, University of Calcutta, Kolkata, West Bengal, India
The
drop size distribution (DSD) of rain in tropical region shows the
characteristic features of different types of rain, namely, stratiform,
transitional and convective. This is also indicated in behaviors of the rain
decay parameter, obtained from the measurements of rain rate and attenuation
over an earth-space path. The DSD parameters and rain decay parameter give
similar clustering indicating the feature of convective and stratiform rain. To
predict rain attenuation from rain rate, the decay parameter is modeled for
different rain rate regions that provides a good matching between the predicted
and measured values.
09:00 F03.4 THE DEVELOPMENT OF AN EMPIRICAL MODEL FOR
SINGLE TREE TRUNK RE-RADIATION PATTERN FOR DRET MODEL APPLICATIONS
This
paper presents the work carried out in an effort of modelling the scattering
and absorption effects of single tree trunks with application to the discrete
Radiative Energy Transfer (dRET) based model applications. The assessment of
the proposed empirical model was performed against measurements of both
metallic and dielectric cylinders, mimicking tree trunks, at several micro- and
millimetre wave frequencies, i.e. 9.4, 18.8 and 37.6 GHz. These were carried
out in a controlled environment, i.e. an anechoic chamber, so that frequency
dependent effects could be evaluated.
09:20 Tea/Coffee Break
09:40 F03.5 POLARIMETRIC SCATTERING AND RADAR ECHOES
FROM INHOMOGENEOUS SCATTER MEDIA WITH ROUGH INTERFACES
Y.-Q. Jin, Fudan University, Shanghai, China
A
theoretical model of stratified lunar regolith media with scatterers and rough
interfaces for numerical simulation of polarimetric radar pulse echoes are
developed. The lunar layer consists of the low lossy regolith layer with
randomly rough top and bottom interfaces, and a layer of random
stone-scatterers (spatially oriented oblate spheroids are assumed) is embedded
and overlays the underlying rock media. The time domain Mueller matrix solution
derived from vector radiative transfer formulations contains seven scattering
mechanisms of the stratified media: surface scattering from the rough top and
bottom interfaces, volumetric scattering from random stone scatterers, and
their multi-interactions.
10:00 F03.6 ON THE USEFULNESS OF SELECTED RADIO WAVES
PROPAGATION MODELS FOR DESIGNING MOBILE WIRELESS SYSTEMS IN CONTAINER TERMINAL
ENVIRONMENT
S. J. Ambroziak, R. J. Katulski, Gdansk University of Technology, Gdansk, Poland
Modelling
of basic transmission loss in container terminal is difficult, so it is
important to determine which propagation model is the most usefulness for it.
At the outset of the paper the applied research methodology have been
presented. Next, the selected propagation models have been shortly
characterized. These models are: ITU-R P.1411-4, COST231 Walfisch-Ikegami and
empirical model for fixed radio networks in the container terminal. The main
part of the paper presents results of verification, based on mean error and
standard error of estimate. Future research aimed at developing new propagation
model have been shortly presented.
10:20 F03.7 PREDICTION OF DIFFRACTION EFFECTS DUE TO
IRREGULAR TERRAIN ON RADIO WAVE PROPAGATION IN THE VHF AND UHF BANDS
Many
models have been proposed to represent diffraction effects on the propagation
of radio waves over irregular terrain in the VHF and UHF bands. Predictions
from these models have been compared with results from field-strength
measurements available in extensive databases that also incorporate the
technical parameters of thousands of VHF and UHF links. Possible sources of the
still high values of the standard deviations of errors between predictions and
measurements will be identified and discussed, with particular attention to
uncertainties on digital elevation models and on the effective Earths radius,
as well as to effects from lateral propagation.
10:40 F03.8 RADIO WAVE DIFFRACTION BY TERRAIN
IRREGULARITIES
M. S. Assis, Fluminense Federal University, Niteroi, RJ, Brazil
This
paper deals with the problem of diffraction by terrain irregularities. To avoid
the difficulties associated to the general solution, which is given by an
integral equation, simplified methods for the evaluation of radio wave
attenuation are available. However, the accuracy of these methods depends on
restrictions imposed by frequency, link parameters (path distance and antenna
heights) and terrain profile. In this paper emphasis is given to the work that
is being carried out in the Study Group 3 (Radiowave Propagation) of ITU-R
(Radiocommunication Sector of the International Telecommunication Union).
11:00 F03.9 COMPUTING THE INFLUENCE OF WIND TURBINES
ON RF SYSTEMS TAKING INTO ACCOUNT TERRAIN.
E. H. Van Lil, J.-W. De Bleser, A. R. Van de Capelle, K.U.Leuven, Heverlee, Brabant, Belgium
Previous
studies have focused on the influence of moving objects such as wind turbines
on aeronautical and maritime radars, usually working in the L/S band and in the
X-band respectively. Here, we will not only take into account terrain
properties, but also compute systems very close to each other and at lower
frequencies, where UTD is no longer valid. In addition, particular attention
will be paid to the computations of systems that are in the near-field of the
antenna.
11:20 F03.10 THE JOINT INVERSE FILTERING AND PARAMETRIC
IDENTIFICATION FOR COMPLEX RADAR IMAGE
The
paper suggests combining the inverse filtering and the parametric
identification in the post-processing sequence of the complex radar image. The
image can be modeled assuming the superposition of the identical partial
responses from the effective target point-scatterers. Their positions
correspond to the geometrical profile of target in the image coordinate plane.
The proposed algorithm of radar image post-processing consists of the
parametric and the non-parametric procedures which are used to improve the
image resolution and to identify geometrical form of the target. The presented
simulated results illustrate the main steps of radar image post-processing.
11:40 F03.11 COMPARISON OF HYDROMETEOR ATTENUATION ON
PARALLEL TERRESTRIAL PATHS AT 58 GHZ AND 93 GHZ
The
results of 3-year experimental research of attenuation due to hydrometeors at
58 GHz and 93 GHz parallel terrestrial paths are given. The obtained cumulative
distributions of attenuation due to all the hydrometeors combined, monthly
cumulative distributions of attenuation due to all the hydrometeors combined,
cumulative distributions of attenuation due to the individual hydrometeors
separately, and cumulative distributions of rain intensities are given. The
influence of individual hydrometeors on attenuation is analysed. The obtained
cumulative distribution of attenuation due to rain only is compared with the
calculated one in accordance with the relevant ITU-R recommendations.
12:00 End of the Session
G03 - Recent Developments in and Coordinated Studies with Incoherent Scatter Radars
Session Chairs: Anja Strømme, Ian McCrea, Ingemar Haggstrom
Session G03
Type Oral Presentation
Schedule Tuesday, August 16, 08:00-12:00
Room Topkapi A
08:00 G03.1 GLOBAL SCALE IONOSPHERIC MONITORING -
FUTURE DEVELOPMENT
Incoherent
scatter radars have developed considerably in recent years with the deployment
of multiple new systems (Poker Flat, Alaska, Resolute Bay, Canada, and in
development in China, Argentina, Antarctica, and Scandinavia, as well as a
second system at Resolute Bay) and operational changes to support continuous
and remote measurements. We will discuss plans to add further observational
sites, built around phased array incoherent scatter radars, to cover a complete
geomagnetic meridian; plans to further integrate the routine operation of many
radars around the globe; and the potential for hardware collaboration for
future incoherent scatter radar systems.
08:20 G03.2 COMPARATIVE STUDIES OF HEATING AND ION
UPFLOW AT SONDRE STROMFJORD AND EISCAT
Although
the Sondrestrom radar is at a lower geographic latitude than any of EISCATs
mainland radars, its geomagnetic latitude and dip angle are comparable to those
of the EISCAT Svalbard Radar. In this study, we compare the statistics of ion
upflows observed at Sondrestromfjord with those obtained at EISCAT (Tromso and
Svalbard) during comparable periods. We will also look at the underlying
variations in ion and electron temperature which play a role in driving these
outflow events, and discuss the extent to which the relationship between
geomagnetic and geographic latitude might contribute to the differences
observed.
08:40 G03.3 POLAR CAP ELECTRIC FIELD OBSERVATIONS FROM
THE RESOLUTE BAY INCOHERENT SCATTER RADAR
H. Bahcivan, M. J. Nicolls, C. J. Heinselman, SRI International, Menlo Park, United States
The
new incoherent scatter radar in Resolute Bay (RISR) is providing first-time
observations of fine-scale spatial and temporal electric potential structures
in the polar cap ionosphere. The sub-minute resolution ionospheric convection
response can be intimately tied to solar wind magnetic pulses measured by the
ACE and WIND spacecraft. Furthermore, we present estimates of electric
potential maps (over ~ 500x500 km latitudinal and longitudinal extent)
constructed using simultaneous multi-beam position line-of-sight velocity
measurements and new inversion techniques. The electric field divergence
averaged over the mapped region shows diurnal variation consistent with a
two-cell convection pattern.
09:00 G03.4 DETERMINATION OF PRECIPITATING ELECTRON
FLUXES FROM INVERSION OF COORDINATED ALIS/EISCAT OBSERVATIONS.
In
March 2008, discrete stable auroral arcs were investigated during a coordinated
observational campaign between the European Incoherent Scatter Radar (EISCAT)
and the Auroral Large Imaging System (ALIS). The two sets of data are inverted
to retrieve fluxes of precipitating electrons. Both results are matching in
energy and shape with a typical average precipitation energy of a few keV.
Finally, by using the average energy spectrum of electrons deduced from ALIS
data as input for the TRANS4 kinetic/fluid electron transport 1D model,
computed auroral emissions are compared to ALIS observations and electron
density profiles are compared to EISCAT profiles.
09:20 Tea/Coffee Break
09:40 G03.5 EISCAT_3D: EUROPES NEXT-GENERATION RADAR
FOR STUDIES OF THE UPPER ATMOSPHERE AND GEOSPACE
I. W. McCrea, STFC Rutherford Appleton Laboratory, Harwell, Oxfordshire, United Kingdom
EISCAT
is leading a Preparatory Phase project for EISCAT_3D, a new multistatic phased
array system, to replace its radars in Scandinavia. EISCAT_3D will be the most
advanced IS radar yet constructed, combining multiple beams, advanced imaging,
flexible signal processing and greatly improved resolution and sensitivity. The
Preparatory Phase will resolve the technical, financial, logistical and
political issues to be clarified before construction. It began in October 2010
and continues until September 2014. We will review the objectives of the study,
summarise its current status, look ahead to future challenges, and report on
the supporting actions contributing to EISCAT_3D development.
10:00 G03.6 MULTISCALE SOFTWARE RADAR NETWORKS AND THE
GEOSPACE ARRAY
F. D. Lind, MIT Haystack Observatory, Westford, MA, United States
Ground
based Incoherent Scatter Radar has provided a sustained record of observation
and scientific discovery. However, these systems are limited by the ad-hoc and
incremental nature of their creation, the diverse technologies used, and the
costs associated with maintenance and operations. It is difficult to break free
of these limitations and addressing them requires a paradigm change. We will
discuss how multi-scale software radar arrays could result in a global array
for observation of the Geospace environment. We will also highlight how the
development of EISCAT 3D radar system is a major step in this direction.
10:20 G03.7 THE EISCAT_3D ARBITRARY WAVEFORM EXCITER
AND POLYPHASE CONSTANT AMPLITUDE CODES FOR EISCAT VHF AND ESR D/E LAYER
EXPERIMENTS
The
AD9957 fast digital up-converter has been found to possess most of the
qualities required to implement the beam-steering and arbitrary waveform
capabilities of the EISCAT_3D radar system. An exciter system based on the
AD9957 is now under construction. As an integral part of this programme, two
constant-amplitude polyphase experiments with excellent D- and E-region
properties have been developed. One of these will be tested on the existing
EISCAT radars during the 2011 PMSE season. The AD9957, the exciter and the
polyphase codes will be presented; results and conclusions from the test
experiments will be reported.
10:40 G03.8 THE EFFECTS OF COULOMB COLLISIONS ON H+
AND HE+ PLASMAS FOR TOPSIDE INCOHERENT SCATTER RADAR APPLICATIONS AT JICAMARCA
To
continue the work of Milla and Kudeki [2011] on Coulomb collisions, we have
recently started the development of a multi-component collisional incoherent
scatter spectrum model that considers O+, H+, and He+ plasmas as needed for
topside perpendicular-to-B observations at Jicamarca. The spectrum model is
being developed based on simulations of particle trajectories in magnetized
plasmas where collision effects are modeled by friction and diffusive forces
with expected values taken from the Fokker-Planck equation of Rosenbluth et al.
[1957]. In this presentation, we will report on our advances on the development
of this new spectrum model.
11:00 G03.9 EISCAT APERTURE SYNTHESIS IMAGING (EASI_3D)
FOR THE EISCAT_3D PROJECT
C. La Hoz, V. Belyey, University of Tromso, Tromso, Norway
Aperture
Synthesis Imaging Radar (ASIR), code-named EASI_3D, is the technology adopted
by the EISCAT_3D project to give imaging capabilities in 3-dimensions including
sub-beam resolution. Complemented by pulse compression, it will provide
3-dimensional images of certain types of incoherent scatter radar targets
resolved to about 100 metres at 100 km range. This ability will open new research
opportunities to map small structures associated with non-homogeneous, unstable
processes such as aurora, summer and winter polar radar echoes (PMSE and PMWE),
Natural Enhanced Ion Acoustic Lines (NEIALs), structures excited by HF
ionospheric heating, meteors, space debris, and others.
11:20 G03.10 THE D-REGION IONOSPHERE DURING THE SOLAR
MINIMUM AS SEEN BY THE EISCAT SVALBARD CONTINUOUS 1-YEAR IPY RADAR EXPERIMENT
The
EISCAT Svalbard Radar (ESR) was operated in a continuous mode during the
International Polar Year (IPY), starting on 1 March 2007 and ending on 29
February 2008. The radar experiment was dedicated to ensure good coverage also
in the ionospheric lower E and D regions, in addition to covering the more
standard experiment target, the ionospheric F peak, and reaching into the
topside ionosphere. By using this unique continuous dataset gathered during the
solar minimum, we show that anomalous variability of the quiet daytime electron
density in the D region can be explained by the varying NO concentration.
11:40 G03.11 RADIO AURORA EXPLORER TO PROVIDE COHERENT
SCATTER CAPABILITY FOR UHF INCOHERENT SCATTER RADARS
The
Radio Aurora Explorer Cube-Sat mission is a ground-to-space bi-static radar
experiment utilizing UHF incoherent scatter radars (PFISR, RISR, Millstone,
ESR, and Arecibo) to measure plasma turbulence from mid-to-high latitudes in
the altitude range 80-500 km. The experiment provides common-volume
measurements of (1) ionospheric irregularities with high spatial/angular
resolution and (2) quiescent plasma parameters using incoherently scattered
signals. RAX I was launched in 11/2010 and conducted a successful radar
experiment with PFISR; however, it is currently experiencing power issues.
Meanwhile, RAX II is to be launched in 10/2011.
12:00 End of the Session
H03 – Wave-particle Interactions and Their Effects on Planetary Radiation Belts I
Session Chairs: Jacob Bortnik, Craig Rodger, Bruce Tsurutani, Richard Horne
Session H03
Type Oral Presentation
Schedule Tuesday, August 16, 08:00-12:00
Room Topkapi B
08:00 H03.1 MODELING PITCH ANGLE SCATTERING OF
RADIATION BELT PARTICLES BY THE INJECTION OF LOW FREQUENCY WAVES WITH F-REGION
HF-DRIVEN IONOSPHERIC CURRENTS
Injection
of EMIC and Alfven waves into Earths inner radiation belt to pitch-angle
scatter energetic electrons and protons provides active means to study the
physics of the inner radiation belt. We present a new concept of generating
ionospheric currents in the ULF/ELF range with modulated F-region HF heating
using ground-based transmitters even in the absence of electrojet currents that
is applicable to the Arecibo ionospheric heater. A numerical model is used to
simulate the generation and injection of Alfven waves by the Arecibo heater and
their interaction with the trapped protons and suggest future experiments.
08:20 H03.2 ELECTROMAGNETIC ION CYCLOTRON WAVES AND
GEOMAGNETIC STORMS: GOES AND CRRES OBSERVATIONS
B. J. Fraser, A. J. Halford, University of Newcastle, allaghan, NSW 2308, Australia
In
situ observations in the magnetosphere were undertaken to further pursue the
relationship between geomagnetic storms and electromagnetic ion cyclotron
(EMIC) waves using GOES and CRRES satellite data. Thirteen of 22 storms showed
EMIC waves occurring during the main phase. With CRRES storms were divided into
three phases: pre-onset, main, and recovery. The majority, 56%, of storm time
EMIC waves were found to occur during the main phase, while 36% were observed
in the recovery phase.
08:40 H03.3 ION HEATING BY FAST MAGNETOSONIC WAVES AND
RING CURRENT-ELECTRON RADIATION BELT COUPLING
We
present fast magnetosonic waves observed by CLUSTER and study their effects on
the ion distribution and the excitation of EMIC waves. By modelling the narrow
spectral features of the waves we show that ion energy diffusion is more than
two orders of magnitude larger than pitch angle diffusion. The waves fill in
the ion ring distribution and heat the ion tail creating a large anisotropy at
high energies which may be unstable to EMIC waves. The waves can couple the
ring current to the electron radiation belt directly via electron diffusion,
and indirectly via excitation of EMIC waves.
09:00 H03.4 THE THEORY AND NUMERICAL MODELLING OF NON
LINEAR WAVE PARTICLE INTERACTIONS IN OBLIQUE WHISTLERS
This
work reports on a one dimensional fully nonselfconsistent relativistic code
that computes nonlinear resonant electron trajectories in an obliquely
propagating arbitrary VLF wavefield. By defining a generalised phase for the
nth resonance the distribution function of resonant electrons is computed for
any order n by backward trajectory integration and using Liouvilles theorem.
Each resonance order n obeys the trapping equations. A detailed chorus
wavefield model showed strong trapping with a phase space hole for n=1
resonance and a phase space hill for the n=0 resonance. One pass resonant
particle energisation up to 0.4keV were found.
09:20 Tea/Coffee Break
09:40 H03.5 TRIGGERING PROCESS OF WHISTLER-MODE CHORUS
EMISSIONS IN THE MAGNETOSPHERE
Y. Omura, Kyoto University, Uji, Kyoto, Japan; D. Nunn, University of Southampton, Southampton, U.K.
Chorus
emissions are triggered from the linear cyclotron instability driven by temperature anisotropy
of energetic electrons. They grow as an absolute nonlinear instability near the
equator due to an electron hole in velocity space. The transition process from
the linear growth to the nonlinear growth with a rising tone frequency is due
to formation of a resonant current anti-parallel to the wave magnetic field.
The rising-tone frequency introduces a phase shift to the electron hole,
resulting in a resonant current anti-parallel to the wave electric field, which
causes the nonlinear growth. Theory and simulations are presented.
10:00 H03.6 THEORY AND SIMULATIONS OF DISCRETE VLF
EMISSIONS IN THE MAGNETOSPHERE
We
consider the results of theoretical and numerical studies of the of generation
discrete VLF emissions in the Earth's magnetosphere. The physics of cyclotron
wave-particle interactions will be reviewed and current ideas on the mechanism
forming the discrete spectrum of whistler-mode waves will be discussed. Two
most important classes of the discrete emissions, i.e., triggered and chorus
signals will be considered, and their common and specific features will be analyzed.
We discuss the relationship between the model results and observations, and
also possible application of similar mechanisms to the phenomena in the
ion-cyclotron frequency range.
10:20 H03.7 PARTICLE-WAVE-PARTICLE INTERACTIONS
INVOLVING WHISTLER-MODE WAVES IN THE MAGNETOSPHERE.
D. R. Shklyar, Space Research Institute of Russian Academy of Sciences, Moscow, Russian Federation
Search
for and understanding of mechanisms for particle energization is a key problem
in physics of the Earths radiation belts. A good deal of suggested mechanisms
is related to resonant interactions between waves and energetic particle. In
the plasmaspheric region of the magnetosphere, energy density variation of resonant
particles is often much larger than the wave energy density. By examples of
whistler-mode wave-electron interactions we emphasize that, in many cases, the
energy increase (decrease) of resonant particles is related to energy transfer
from (to) other group of resonant particles, while the wave basically mediates
the energization process.
10:40 H03.8 CHORUS VARIATION DURING THE COMPRESSION OF
MAGNETOSPHERE
Chorus
is important in space science due to its role in generation of relativistic
electrons in the Van Allen radiation belts, which are hazardous to satellites
and astronauts. Although chorus has been studied for several decades and many
theories have been proposed, its generation and growth mechanisms are still not
well understood. In this manuscript, we show an unexpected observation, based
on measurements from the NASA THEMIS satellites, that chorus can be
significantly amplified when an interplanetary shock that originates from Sun
hits Earths magnetosphere. The shock-induced anisotropic distribution of
energetic electrons leads to the growth of chorus.
11:00 H03.9 UNUSUAL OBSERVATION OF CHORUS AT L=2.6
On
the 4th August 2010, chorus was observed on Marion Island (L=2.6). A similar
event was observed at Palmer Station, Antarctica (L=2.44) during the Halloween
Storms of 2003. The spatial extent of the 2010 event is discussed and data from
several systems, including DEMETER VLF, GPS particle and AARDVARK precipitation
data are analysed. We investigate the location of the plasmapause with
satellite data. Preliminary analysis of low resolution VLF data from other mid
and high latitude stations show that a similar emission was observed at these
sites, but at different times.
11:20 H03.10 DIFFUSION-ADVECTION MODELING OF
WAVE-PARTICLE INTERACTIONS IN THE RADIATION BELTS
J. M. Albert, Air Force Research Laboratory, Hanscom AFB, MA, United States
Properly
treating wave-particle interactions is crucial to modeling and predicting the
behavior of radiation belt electrons. The usual quasi-linear theory alone
cannot capture the effects likely to be caused by nonlinear interactions with
coherent waves, particularly chorus. Detailed analytical estimates of nonlinear
particle motion in a specified wave have been developed, and and combined with
detailed wave models can be used to formulate a combined diffusion-advection
equation for the electron phase space density. Quasi-linear diffusion is
recovered for small amplitude waves, but phase bunching and phase trapping,
caused by larger amplitude waves, can also be included.
11:40 H03.11 RELATIVISTIC MICROBURST STORM
CHARACTERISTICS: COMBINED SATELLITE AND GROUND-BASED OBSERVATIONS
We
report a comparison of SAMPEX detected relativistic electron microbursts and
short-lived subionospheric VLF perturbations termed FAST events, observed at
Sodankyl Geophysical Observatory, Finland, during 2005. The observed FAST event
perturbation decay times were consistent with ionospheric recovery from bursts
of relativistic electron precipitation. Our study strongly suggests that the
region over which microbursts occur during storm event periods can be at least
~90 in longitude (~6 hours in MLT). This confirms earlier estimates of
microburst storm size, suggesting that microbursts could be a significant loss
mechanism for radiation belt relativistic electrons during geomagnetic storms.
12:00 End of the Session
J03 – Technology Development for the SKA Program
Session Chairs: Ken Kellermann, Richard Schilizzi
Session J03
Type Oral Presentation
Schedule Tuesday, August 16, 08:00-12:00
Room Marmara
08:00 J03.1 POWER CONSIDERATIONS FOR THE SQUARE
KILOMETRE ARRAY (SKA) RADIO TELESCOPE
The
SKA will be the world's most sensitive radio telescope and is expected to be
fully operational below 10 GHz by 2023. It will extend over more than 3000 km
but over half its collecting area will be located at one of two remote,
radio-quiet sites in either Australia or South Africa. The instrument will
collect and process vast amounts of information, and the provision of reliable,
affordable electrical power over a 30-50 year operational lifetime is a major
challenge. This paper outlines some of the issues and a few exemplar
innovations in the SKA power area.
08:20 J03.2 THE SKA RFI AND TROPOSPHERIC SITE TESTING
PROGRAM
R. P. Millenaar, SPDO, Manchester, United Kingdom
The
Square Kilometre Array project will soon decide upon where this new large radio
telescope will be located, on the basis of a range of criteria. Two
environmental aspects are examined for maximum scientific return through
measurements at candidate sites: the radio frequency interference (RFI) and
tropospheric environments. High sensitivity as well as high speed measurements
will make an inventory of the RFI at the core sites and at a selection of
remote sites. Tropospheric phase stability will be investigated using two
identical interferometer systems pointed to geostationary satellites, in a
campaign lasting at least one year. A report.
08:40 J03.3 SIGNAL TRANSPORT AND NETWORKS FOR THE SKA
R. McCool, The SKA Programme Development Office, Manchester, United Kingdom
The
signal transport and networks of the SKA are the backbone of the telescope;
they interface with almost every aspect of the system. They provide services,
fundamental to the operation of the SKA as an aperture synthesis
interferometer, such as timing and synchronisation and the transmission of data
from receptors to a correlator. Signal transport and networks provide
communication links both internally to the telescope and externally to the SKA
regional centres around the world. This paper will describe the requirements
placed on these networks by the telescope and the technical progress in
developing solutions to deliver this required functionality.
09:00 J03.4 REFLECTOR ANTENNAS (DISHES) FOR THE SQUARE
KILOMETRE ARRAY (SKA)
P. E. Dewdney, N. Roddis, University of Manchester, Manchester, United Kingdom
Parabolic
reflectors (dishes) are the most general purpose, flexible antennas used in
radio astronomy, typically able with multiple feeds to cover two orders of
magnitude in frequency. The SKA requirements will push the limits of dish
design for decimetre wavelengths beyond that of any existing dishes. The SKAs
sensitivity as well as its wide-field imaging requirements push performance
limits, while the need to produce and deploy thousands of dishes in an array
spanning continental baselines push cost and fabrication limits. This paper
will discuss SKA requirements and a combination of techniques being brought to
bear on this design problem.
09:20 Tea/Coffee Break
09:40 J03.5 THE SYSTEM DESIGN FOR THE SQUARE KILOMETRE
ARRAY (SKA)
K. Cloete, P. E. Dewdney, SKA Program Development Office, Manchester, United Kingdom
As
a global project the Square Kilometre Array (SKA) engineering activities are
conducted in parallel at many levels and within many global institutions and
companies. While the SKA will offer huge science impact, the myriad of
potential solutions to its technical challenges put forward and the sheer
complexity of the telescope system indicate a rigorous systematic approach. In
projects of this scale, the discipline of system engineering has been found to
be the key to a successful, focussed design. This paper will present the
approach, progress, status and challenges of the system design effort of the
SKA.
10:00 J03.6 GENERIC CONFIGURATIONS FOR THE SKA
We
have developed generic layouts for both Phase 1 and Phase 2 of the Square
Kilometre Array. We present these layouts here and show some examples of their
sensitivity performance in the uv domain. These layouts are useful for
providing comparisons between "ideal" layouts and those that meet the
siting constraints arising in reality where geography and human activity limit
the accessible terrain.
10:20 J03.7 MEASUREMENT OF A 10 METRE COMPOSITE RADIO
DISH SURFACE SHAPE BETWEEN 2008 AND 2010
G. Lacy, A. Gray, National Research Council, Penticton, BC, Canada
A
composite radio reflector (the MkII) was molded at the Dominion Radio
Astrophysical Observatory (DRAO) in 2008. The MkII was built as a demonstrator
for the International Square Kilometre Array (SKA). Since 2008, the MkII has
been used to test a prototype Phased Array Feed (PHAD). This PHAD demonstrator
puts a substantial load on the structure. The MkII telescope has also been used
to investigate composite thermal and weathering issues. The surface shape of
the main reflector were recorded in 2008 and again in 2010 using a laser
scanner. These data are compared. Some interesting results are presented.
10:40 J03.8 PHASED ARRAY FEEDS FOR THE SQUARE
KILOMETRE ARRAY
A
novel method to form multiple instantaneous beams on the sky with a reflector
antenna is to employ a dense Phased Array Feed (PAF). This technology is
currently being developed to greatly increase the survey speed of existing and
future radio telescopes. This paper reviews the current state of PAF
development projects at several international radio astronomy institutes, the
particular challenges and the potential for incorporation of PAFs into the
ultimate radio survey instrument: the Square Kilometre Array.
11:00 J03.9 DENSE APERTURE ARRAYS FOR THE SQUARE
KILOMETRE ARRAY
A. J. Faulkner, University of Cambridge, Cambridge, United Kingdom
Aperture
phased arrays operating up to 1.4 GHz are an exciting technology for the Square
Kilometre Array, SKA. Phased array stations bring major scientific
opportunities including high survey speeds, flexible searching for transient
phenomena, and multi-beaming capability not possible with other collectors. The
technological requirements of high frequency phased arrays are severe with the
channel count and required digital processing. Roadmapping shows that technical
developments make a system realistic from 2018. The Aperture Array Verification
Program, AAVP, is working on a sparse low frequency array and a dense array
from 400MHz to 1450MHz for the SKA.
11:20 J03.10 WIDEBAND FEEDS AND LOW NOISE AMPLIFIERS
FOR LARGE ARRAYS
S. Weinreb, A. Akgiray, D. Russell, California Institute of Technology, Pasadena, CA, United States
The
state of the art for feeds and LNAs with frequency ranges approaching one
decade will be presented. These components reduce the cost of receivers
required to cover a given frequency range and enable observations requiring
large bandwidth such as spectral index measurements, search for spectral lines
with unknown red shift, and detection of transient events. An example of a 2 to
12 GHz feed will be given and compared in efficiency with an octave band feed.
Low noise amplifiers for the 0.5 to 12 GHz range utilizing HEMT and SiGe
bipolar transistor will be desribed.
11:40 J03.11 PATHFINDERS AND PRECURSORS FOR THE SKA
J. M. Cordes, Cornell University, Ithaca, New York, United States
I
will discuss pathfinding activities in science, technology development and
cyber-infrastructure that are relevant to the Square Kilometre Array.
Technology development includes work on dish antennas, wideband dipole arrays,
wideband feed antennas, and widefield phased array feeds. Science applications
include time-domain exploration, deep continuum imaging, and high-rate surveys.
The implied data volumes are growing exponentially and need to be matched with
data management and mining systems.
12:00 End of the Session
K03 – Environmental EMF Exposure Assessment
Session Chairs: Yngve Hamnerius, Georg Neubauer
Session K03
Type Oral Presentation
Schedule Tuesday, August 16, 08:00-10:40
Room Loft
08:00 K03.1 ASSESSMENT OF THE REAL LIFE EXPOSURE TO 2G
AND 3G BASE STATIONS OVER A DAY FROM INSTANTANEOUS MEASUREMENT
In
this paper, the general public daily exposure to mobile telephony is
investigated. The considered signals are GSM900, GSM1800, UMTS and HSDPA. The
study focus on the assessment of the maximal real electric field received over
the day from an instantaneous measurement performed any time during the day. An
extrapolation factor is presented to extrapolate an instantaneous measurement
for any signal to the maximal possible value received by this signal over the
day. This factor is also given to extrapolate the total electric field received
to his possible maximum value over the day.
08:20 K03.2 DISTRIBUTION OF ELF MAGNETIC FIELDS IN
SWEDISH DWELLINGS
The
distribution of ELF magnetic fields in randomly selected Swedish dwellings has
been assessed. The results show that 89 % of the measured houses have average
magnetic fields below 0.2 uT with mean value of 0.11 uT and median value 0.05
uT. Comparing villas and apartments show that the median magnetic fields value
for apartments is 0.07 uT compared to 0.04 uT for villas. The dominating
frequency of the magnetic field was 50 Hz. The total harmonic distortion (THD)
of the magnetic field was measured; the median value of THD was 10.3 %.
08:40 K03.3 A EUROPEAN INITIATIVE TO DEVELOP
PROCEDURES AND INSTRUMENTATION FOR WORKER'S ELECTROMAGNETIC SAFETY (WEMS)
A
project is described that is developing procedures and instrumentation to
demonstrate compliance with EU Directive 2004/40/EC. In 2012, the directive
will pose new requirements on employers in the European Union to evaluate the
exposure of workers to electromagnetic fields (EMF). Implementation of these
requirements is a significant challenge to employers, many of whom lack the
resources and expertise required to demonstrate compliance with EMF limits.
Some industries that use high-current or high-voltage equipment in the
workplace are particularly affected, such as the automotive, railway and metal
fabrication industries. Simple and reliable tools are necessary for employers
in these industries.
09:00 K03.4 A NEW WEB BASED SYSTEM TO EVALUATE WORKERS
EXPOSURE ACCORDING TO REQUIREMENTS OF THE DIRECTIVE 2004/40/EC
H. Molla-Djafari, Austrian Institute of Technology GmbH, Seibersdorf, Austria
The
Directive 2004/40/EC of the European Commission has the purpose to protect
workers against adverse affects from electromagnetic fields (EMF). To achieve
this several requirements are imposed on employers that can be hardly managed
by them. It was therefore decided to develop a software system dedicated to
enable employers to evaluate the exposure of their employees without having any
specific expertise on EMF. This Austrian system called EMES has a database with
distance depending exposure data from about 1.000 electromagnetic sources. The
exposure arising from all selected sources is calculated and compared to the
limits .
09:20 Tea/Coffee Break
09:40 K03.5 ELECTROMAGNETIC SOURCE MODELING USING
PHASE RETRIEVAL METHODS
Modeling
of the field distributions from electromagnetic sources is of interest for
various applications for example electromagnetic compatibility investigations,
near-field to far-field transformations, antenna diagnostics and
electromagnetic dosimetry. In order to determine whether exposure safety
guidelines, such as the EU directive 2004/40/EC, are complied with, source
modeling methods are important. Methods for determining the total field,
including phase information, when only field amplitudes have been measured on a
set of planes in front of an electromagnetic source have been developed.
Promising results have been obtained both for numerical test cases and for
measured field.
10:00 K03.6 EXPOSURE CHAMBERS FOR VERIFICATION OF
MICROWAVE INFLUENCE ON BIOLOGICAL SYSTEMS
J. Vrba, L. Visek, Czech Technical University in Prague, Prague, Czech Republic
The
main aim of our work is to design and simulate an exposure chamber in order to
analyze the influence of electromagnetic field on mice which can simulate
mobile phone emission patterns. We use two types of structures and compare
their properties to find the best design for our future work.
10:20 K03.7 RESEARCHING OF FERROMAGNETIC INCLUSIONS
INFLUENCE ON PROTECTING PROPERTIES OF SHIELDING COMPOSITE MATERIALS WITH
DIELECTRIC AND MAGNETIC STRUCTURE ELEMENTS
H. Pukhir, BSUIR, Minsk, Belarus
The
effect of ferromagnetic impurities in electromagnetic absorbers is studied. It
has established that a small amount of magnetic powder in composite structure
influence on attenuation and reflection characteristics of shielding material.
These magnetic inclusions can increase the attenuation at 15 dB and reflection
coefficient at 2,5 dB in comparison with dielectric samples. The compound with
powders of silica and nickel-zinc ferrite as a base of shielding composite has
investigated. The dependence of the shielding characteristics of the composite
is shown. The use of these composite materials for creation of electromagnetic
shielding constructions are considered.
10:40 End of the Session
C05 – Radio Science for Information Security and Social Safety
Session Chairs: Takashi Ohira, Satoru Aikawa, Masamune Takeda
Session C05
Type Oral Presentation
Schedule Tuesday, August 16, 10:20-12:00
Room Dolmabahçe A
10:20 C05.1 A KEY GENERATION TECHNIQUE USING ARRAY
ANTENNA BEAM SELECTION
S. Aikawa, Graduate school of Engineering, University of Hyogo, Himeji, Hyogo, Japan
Recently,
secret key generation schemes for wireless communication systems using
propagation performance are researched. RSSI, signal strength indications
received at AP (Access Point) and UT (User Terminal) are same value in TDD
systems because of reciprocity theorem, and are controlled by the array antenna
pattern. However, RSSI at TP (Tapping Point) is not same as RSSI at AP or UT
that depend on their location. The secret keys are generated from binarized
RSSIs. This paper describes a method for improving the probability of key
agreement between AT and UT by using array antennas control.
10:40 C05.2 EXPERIMENTAL VALIDATION OF WIRELESS SECRET
KEY AGREEMENT USING ARRAY ANTENNAS
T. Shimizu, N. Otani, T. Kitano, H. Iwai, H. Sasaoka, Doshisha University, Kyotanabe, Kyoto, Japan
This
paper considers the problem of wireless secret key agreement based on radio
propagation characteristics, where two legitimate parties generate and share a
secret key by exploiting the radio propagation characteristics between them in
the presence of an eavesdropper. We developed an experimental system using
array antennas to implement the wireless secret key agreement. In this paper,
we present the experimental system and validate basic characteristics that are
fundamental for the wireless secret key agreement, such as the reciprocity and
position dependence of radio propagation characteristics, with the developed
system.
11:00 C05.3 IMPACT OF DIRECT-PATH WAVE ON IMAC IN
SECRET KEY AGREEMENT SYSTEM USING ESPAR ANTENNAS
Current
cryptography may be potentially decrypted by an extremely high performance
computer. More secure key sharing schemes are expected. One possible solution
is secret key agreement system which makes use of Electrically Steerable
Parasitic Array Radiator (ESPAR) antenna. In this scheme ideally, by using wave
propagation characteristics, eavesdropper cannot guess secret key from regular
terminals. Actually however, eavesdropper has chances to guess the key if he is
located on the line of direct-path wave between regular terminals. In our
study, we evaluate the impact of direct-path wave on Information mutual
anti-tapping condition (Imac) under a noisy channel.
11:20 C05.4 NOVEL TECHNIQUE FOR IMPROVING BLUETOOTH
NETWORKS SECURITY THROUGH SVD-BASED AUDIO WATERMARKING
The
Paper improves the security over IEEE 802.15.1 networks. It proposes a new
approach for audio watermarking using the singular value decomposition (SVD)
mathematical technique. This approach is based on embedding the encrypted image
in the singular values of the audio signal after transforming it into a 2-D
format. After watermark embedding, the audio signal is transformed again into a
1-D format. At the receiver the watermark signal is reconstructed and
extracting the image. The proposed audio watermarking approach maintains the
high quality of the audio signal and that the watermark extraction and
decryption are possible.
11:40 C05.5 DETECTION OF LANDSLIDE USING WIRELESS
SENSOR NETWORKS
Wireless
sensor networking is one of the emerging areas which are extensively being used
for development of real-time monitoring systems. This paper discusses the
development of a wireless sensor network (WSN) to detect landslides, which
includes design and development of WSN for real time monitoring system. A
laboratory trial has been performed using wireless sensor networking with the
integration of different sensors to detect the landslide.
12:00 End of the Session
KT – Epidemiology of RF and Cancer
Session Chair: Emilie Van Deventer
Session KT
Type Oral Presentation
Schedule Tuesday, August 16, 11:00-12:00
Room Loft
11:00 KT.1 EPIDEMIOLOGY OF RF AND CANCER
J. Schüz, International Agency for Research on Cancer, Lyon, France
There
is still an ongoing scientific controversy whether exposure to electromagnetic
fields is associated with an increased cancer risk in humans. Epidemiological
studies have shown a consistent association between exposure to extremely
low-frequency (ELF) magnetic fields and the risk of leukemia in children, but
even after decades of investigations it is unclear whether the observed
association is causal or due to bias and limitations of the studies. The
International Agency for Research on Cancer (IARC) has therefore classified ELF
magnetic fields as possible carcinogenic to humans. Several studies of
different designs investigated the association between radiofrequency (RF)
electromagnetic fields related to the use of mobile phones and the risk of
brain tumors. While short-term use of mobile phones of less than ten years was
not related to any increased tumor risk, uncertainty remains particularly for
longer term heavy users. Mobile phone studies are methodologically challenging
and future study protocols need to reduce limitations observed in studies
available today.
12:00 End of the Session
Session Chair: Sedki Riad
Session A04
Type Oral Presentation
Schedule Tuesday, August 16, 13:40-15:40
Room Dolmabahçe C
13:40 A04.1 AN OVERVIEW OF THE TECHNIQUES FOR
MEASURING THE DIELECTRIC PROPERTIES OF MATERIALS
O. V. Tereshchenko, F. J. K. Buesink, F. B. J. Leferink, University of Twente, Enschede, Netherlands
In
Power Electronics devices, such as modern power supply, EMI filters occupy a
substantial portion of the volume. To achieve a breakthrough an innovative
production process is needed with lower cost, higher reliability, controlled
EMI, controlled quality and a higher level of circuit integration. One of the
most promising approaches in current research is the modification of embedded
electromagnetic interference filters (EMI) through the improvement of their
design and choosing material with the required qualities at an acceptable cost.
To achieve this an overview of the techniques for measuring the dielectric
properties of materials has been done.
14:00 A04.2 ELECTROSTATIC MEASUREMENTS OF LOW
CAPACITANCE CHANGES IN A PARALLEL PLATE CAPACITOR
This
paper describes an electrostatic experimental setup to measure the capacitance
change when an uncharged object of arbitrary shape is inserted into a parallel
plate capacitor. The employed measurement technique is discussed in detail, and
measurements on two conducting spheres and two conducting circular cylinders of
finite height are presented and compared with numerical simulations. It is
concluded that the experimental setup is capable of detecting capacitance
changes down to 10 aF.
14:40 A04.4 DIELECTRIC MATERIAL MEASUREMENTS SUPPORTED
BY ELECTROMAGNETIC FIELD SOLVERS
E. Kilic, U. Siart, C. H. Schmidt, T. F. Eibert, Technische Universitaet Muenchen, Munich, Germany
An
iterative transmission line technique for the determination of complex
permittivity of non-magnetic, isotropic materials is addressed. The method is
based on minimizing the objective function measuring the error between
simulated and measured scattering parameters by classical Newton's method. An
Electromagnetic field solver is used to solve the forward problem which is
repeated in the application of Newton's method at each iteration. Since
full-wave simulation is carried out, the method has no strict limitations on
the geometry of the samples. For validation, proposed method is tested against
partially loaded waveguide measurements at K-band.
15:00 A04.5 MULTI-SCALE ELECTROMAGNETIC BAND GAP
STRUCTURES AND ANTENNA APPLICATIONS
Multi-scale
rectangular mushroom structure, high impedance ground plane (HIGP), is designed
to achieve large band gap. By suppressing surface waves, the structure becomes
eligible for antenna applications. The HIGPs are composed of three different
sized rectangular patch mushroom elements for different resonance frequencies.
The characterizations of the three scaled HIGP with varying all dimensions are
observed for GHz frequency range. Some antenna designs for free space
application and the effect of the multi-scale HIGP on these antennas are also
presented.
15:20 A04.6 RADIO-FREQUENCY TRANSPORT OF SINGLE
ELECTRONS IN SUPERCONDUCTOR-NORMAL-METAL TUNNEL JUNCTIONS AND THE QUANTUM
METROLOGICAL TRIANGLE
We
are developing a single-electron turnstile based on a nanoscale superconductor-insulator--normal-metal--insulator-superconductor
(SINIS) structure. The goal is to obtain the frequency to current conversion
I=ef with a relative uncertainty <10^-8 which would be sufficient for a
quantum-based standard of electric current. Finally, the quantum current
standard will be compared against the quantum standards of voltage and
resistance via Ohm's law in the quantum metrological triangle experiment.
15:40 End of the Session
B04 – Electromagnetic Field Transformations for Measurements and Numerical Methods
Session Chair: Thomas Eibert
Session B04
Type Oral Presentation
Schedule Tuesday, August 16, 13:40-15:40
Room Anadolu Auditorium
13:40 B04.1 SEPARATION OF RADIATION FROM TWO SOURCES
FROM THEIR KNOWN RADIATED SUM FIELD
This
paper presents a technique for complete and exact separation of the radiated
fields of two sources (at the same frequency) from the knowledge of their
radiated sum field. The two sources can be arbitrary but it must be possible to
enclose the sources inside their own non-intersecting minimum spheres so that
the closest distance between the surfaces of the two spheres is of the order of
at least a few wavelengths.
14:00 B04.2 PLANE WAVE BASED NEAR-FIELD FAR-FIELD
TRANSFORMATION WITH ADAPTIVE FIELD TRANSLATIONS
C. H. Schmidt, M. A. Qureshi, T. F. Eibert, Technische Universitaet Muenchen, Munich, Germany
Near-field
transformation algorithms compute the antenna radiation pattern from a
measurement in the radiating near field. The plane wave based near-field
transformation algorithm has a low numerical complexity while achieving full
probe correction and it is applicable to arbitrary measurement grids giving a
huge flexibility for near-field probing. The transmission equation for a set of
measurement points is evaluated in a multilevel fashion and the field
translations are now carried out on different levels depending on the distance
of the measurement point from the antenna. The adaptive field translations allow
to enhance the accuracy of the transformation.
14:20 B04.3 AN IMPROVED IMAGE-BASED
NEAR-FIELD-TO-FAR-FIELD TRANSFORMATION FOR CYLINDRICAL SCANNING SURFACES
An
improved image-based circular NFFFT developed recently for smaller measurement
facilities and for targets with pronounced scattering centers offset from the
center of the imaging area is extended to a cylindrical scanning surface.
Scanning over a surface instead of a circle permits RCS estimations for targets
whose size in the direction perpendicular to the measurement plane is
comparable to their extension in the measurement plane.
14:40 B04.4 NEAR-FIELD ESTIMATION USING A REDUCED
BASIS EXPANSION OF INDUCED MODES IN A HUMAN HEAD MODEL FROM EQUIVALENT SOURCES
A
new approach to evaluate near-field induced by a cellular phone in a human head
model using an E-field expansion into a basis is proposed. This technique is
first based on Huygens principle using equivalent currents on a closed surface
which makes it valid for any cellular phone. Then, using Singular Value
Decomposition, the generated induced E-field by any cellular phones would be
expanded with the orthonormalized modes excited by the equivalent sources in a
human head model. Finally, we estimate the error reconstruction of E-field
using a reduced number of modes.
15:00 B04.5 REFLECTION/TRANSMISSION MEASUREMENT SYSTEM
FOR PLANAR MATERIALS AND VERIFICATION BY THIN WIRE GRIDS
This
paper describes a measurement system to evaluate the reflection and
transmission (R/T) properties of planar materials have been constructed within
the Open-Range EM Laboratory (ASEMLAB) of Gebze Institute of Technology. This
manuscript describes this measurement system, calibration process, and the
results of an application - measurement of the R/T coefficients of a thin wire
mesh. In order to check the measured R/T coefficients of the thin wire mesh a
periodic method of moments (PMM) code has been developed. The currents that
leave one periodic cell and enter the next are handled in a novel way.
15:20 B04.6 METHOD OF MOMENTS ANALYSIS OF AN
AXISYMMETRIC CHIRAL RADOME
An
axisymmetric chiral radome has been analyzed numerically by using the method of
moments. The chiral body is illuminated by a plane wave and the surface
equivalence principle is used to replace the body by equivalent electric and
magnetic surface currents. The scattered fields outside and the total internal
fields are computed with a Matlab computer program that is developed for
axisymmetric chiral radome. Examples of numerical calculations are given for a
chiral spherical radome and chiral Von Karman radome. Numerical results of the
chiral spherical radome are in excellent agreement with the exact ones obtained
by the eigenfunction solution.
15:40 End of the Session
B05 – Theoretical and Numerical Issues in Electromagnetics
Session Chairs: Roberto Graglia, Levent Gurel
Session B05
Type Oral Presentation
Schedule Tuesday, August 16, 13:40-15:40
Room Loft
13:40 B05.1 WELL CONDITIONED HIERARCHICAL NEDELEC
ELEMENTS FOR SURFACE AND VOLUMETRIC CELLS
New
families of hierarchical vector bases for the most commonly used two- and
three-dimensional cells are directly constructed from orthogonal scalar
polynomials to enhance their linear independence, which is a simpler process
than an orthogonalization applied to the final vector functions. These
functions span the mixed-order (or reduced) spaces of Nedelec and can be used
to deal with structures meshed by a mixture of cells of tetrahedral,
hexahedral, and prism shapes. This presentation reviews recent developments of
curl-conforming functions and provides an extension to the
divergence-conforming case.
14:00 B05.2 MATERIAL REALIZATIONS OF EXTREME
ELECTROMAGNETIC BOUNDARY CONDITIONS AND METASURFACES
A. Sihvola, H. Wallen, P. Yla-Oijala, J. Markkanen, I. V. Lindell, Aalto University, Espoo, Finland
The
paper discusses the correspondence between electromagnetic boundary conditions
and interface conditions. In particular, the focus is on the synthetic approach
where the interest is in finding material realizations for given boundary
conditions. Material realizations are approximative but not unique because,
especially if anisotropic and bianisotropic materials are allowed, there are
different material classes with which any given boundary condition can be
mimicked. As examples, the PEC, PMC, PEMC, and DB boundary conditions are
discussed. By comparing the scattering characteristics, it is demonstrated how
well certain extreme-parameter material realizations are able to simulate the
boundary effect.
14:20 B05.3 MOM ANALYSIS OF APERTURES IN CHIRAL BODIES
OF REVOLUTION
A
chiral BOR partially covered by a conducting shield is analyzed using MOM. The
problem is solved using the equivalence principle. Scattered fields outside are
produced by two equivalent surface currents on the BOR surface that radiate in
the unbounded external medium. Internal fields are produced by two surface
currents on the BOR surface. These two currents radiate in the unbounded
internal medium. Boundary conditions at the surface results in a set of coupled
integral equations for unknown currents. They are solved using MOM. Computed
results for the partially shielded spherical chiral body are in excellent
agreement with other data.
14:40 B05.4 MODEL ORDER REDUCTION METHODS FOR
MULTIVARIATE PARAMETERIZED DYNAMICAL SYSTEMS
Electrodynamic
field simulations in the frequency domain typically require the solution of
large dynamical systems. Model order reduction (MOR) techniques offer a fast
approach to approximate the system impedance with respect to the frequency
parameter. During the design process, it is desirable to vary specified
parameters like the frequency, geometry details or material parameters, giving
rise to multivariate dynamical systems. In this work, multivariate MOR methods
are presented for multivariate parameterized systems based on the finite
integration technique. The methods are applied to numerical examples with both
geometrical and material variations.
15:00 B05.5 RIGOROUS SOLUTIONS OF LARGE-SCALE
DIELECTRIC PROBLEMS WITH THE PARALLEL MULTILEVEL FAST MULTIPOLE ALGORITHM
We
present fast and accurate solutions of large-scale electromagnetics problems
involving three-dimensional homogeneous dielectric objects. Problems are
formulated rigorously with the electric and magnetic current combined-field
integral equation (JMCFIE) and solved iteratively with the multilevel fast
multipole algorithm (MLFMA). In order to solve large-scale problems, MLFMA is
parallelized efficiently on distributed-memory architectures using the
hierarchical partitioning strategy. Efficiency and accuracy of the developed
implementation are demonstrated on very large scattering problems discretized
with tens of millions of unknowns.
15:20 B05.6 ANALYSIS OF METAMATERIALS USING ANALYTIC
PROPERTIES
L. Vietzorreck, T. Kim, HFT, Munich, Germany
It
is investigated, how metamaterial structures with a finite number of repeated
cells can be analyzed efficiently. The method of lines, a semi-analytical
method is utilized. As the propagation in propagation direction is described
analytically, Floquet`s Theorem can be used to transform fields at input and
output of one cell into a set of Floquet modes. The propagation of these modes
through N periods can easily be calculated by the phase difference. Thus the
computation time is independent from the period number. Results for a CRLH
transmission line are compared with results of commercial tools and measured
results.
15:40 End of the Session
Session Chair: Jacques Palicot
Session C06
Type Oral Presentation
Schedule Tuesday, August 16, 13:40-15:20
Room Dolmabahçe A
13:40 C06.1 RF POWER SOURCE AND ESTIMATION DIVERSITY
IN DISTRIBUTED SENSING WITH PASSIVE WIRELESS COMMUNICATIONS
A. O. Bicen, O. B. Akan, Koc University, Istanbul, Turkey
Sensor
nodes constitute a distributed wireless sensing architecture, such that,
multiple sensors report their observations. However, sensor networks are
comprised of energy-constrained nodes. Recently, to mitigate battery depletion
problem and extend network lifetime, wireless passive sensor networks (WPSN)
have become a new field of interest. Modulated backscattering is an important
communication technique in WPSN to alleviate reaching unlimited lifetime for
sensor nodes. In this paper, we theoretically analyze event distortion in WPSN
that is employing modulated backscattering for communication. The objective of
this work is to reveal the impact of RF source diversity on event estimation
distortion in WPSN.
14:00 C06.2 A COST FUNCTION EXPRESSION FOR SDR
MULTI-STANDARD SYSTEMS DESIGN USING DIRECTED HYPERGRAPHS
The
design of future multi-standard systems is very challenging. Flexible
architectures exploiting commonalities of different set of standards cohabiting
in the device offer promising solutions. In this paper, graph theory aspects
are introduced with the stress on the notion of directed hypergraphs. These
definitions will be helpful in presenting the theoretical version of the graph
structure of the software-defined radio multi-standard system as a directed
hypergraph, as well as in providing a formal representation of a certain
proposed cost function which computes the cost of any one of the alternatives
which can implement the multi-standard system.
14:20 C06.3 DEVELOPMENT OF 24 GHZ RECTENNAS FOR FIXED
WIRELESS ACCESS
We
need electricity to use wireless information. If we reduce amount of batteries
or electrical wires with a wireless power transmission technology via microwave
(MPT), it is a green communication system. We Kyoto University propose a Fixed
Wireless Access (FWA) system with the MPT with NTT , Japan. In this paper, we
show mainly development results of 24GHz rectennas, rectifying antenna, for
FWA. We developed some types of the rectennas. Finally we achieve 65% of RF-DC
conversion efficiency with output filter of harmonic balance.
14:40 C06.4 HOW TO OPTIMIZE THE SPECTRUM: THE OIL EXPERIENCE
J. Palicot, SUPELEC, Cesson-Svign, France
Since
several years, sustainable development (SD) has become an important issue in
many technical domains. One of the main contributors in CO2 emission is
undoubtly petrol engine. This explains why car industry was the first
interested in finding solutions to decrease oil consumption and to optimize car
usage. Starting from the idea that spectrum is a natural and public resource
which should be carefully used and shared, in this paper we apply to spectrum
usage at every levels (standards, equipments, usage, etc.) analogies coming
from oil experience.
15:00 C06.5 NON UNIFORM SAMPLING FOR POWER CONSUMPTION
REDUCTION IN SDR RECEIVER BASEBAND STAGE
In
this paper, authors point out the effect of non uniform sampling (NUS) on the
power consumption in SDR receiver baseband stage. This feature is drawn by
theoretical formulas regarding spectrum shape and power estimation of different
baseband components. An example is drawn to focus on NUS ability to reduce
anti-aliasing filter (AAF) consumption by 25%.
15:20 End of the Session
DBC – Signal Processing Antennas
Session Chairs: Smail Tedjini, Alain Sibille, H. Chaloupka
Session DBC
Type Oral Presentation
Schedule Tuesday, August 16, 13:40-15:40
Room Dolmabahçe B
13:40 DBC.1 ON THE DIVERSITY PERFORMANCE OF COMPACT
ANTENNA ARRAYS
M. T. Ivrlac, J. A. Nossek, Technische Universitaet Muenchen, Muenchen, Germany
In
contrast to common belief, compact antenna arrays are able to deliver excellent
diversity performance provided that a multiport network is connected between
the array and the receiver which decouples the antenna ports. It turns out that
the diversity performance does not change much as the antenna separation is
reduced below half a wavelength. In fact, the diversity performance even
increases somewhat with reduced antenna spacing. In an isotropic noise
environment, and in the absence of heat loss, excellent diversity performance
can be maintained even as the antenna separation is made arbitrarily small.
14:00 DBC.2 RFID TAGS LOCALIZATION ALONG AN AXIS USING
A TUNABLE NEAR-FIELD FOCUSED CIRCULAR-PHASE ARRAY ANTENNA
A
novel concept for RFID tag localization using a tunable near-field focused
circular-phase array antenna working at 5.8 GHz is presented. It serves as the
reader antenna and focuses the power into a small region, in the tag vicinity.
By scanning the focal spot along one axis and monitoring the differential
scattered power by a tag, its position along the axis is easily computed with
good accuracy. This simple localization scheme is well adapted for specific
localization scheme, for example for objects placed over a conveyor belt.
14:20 DBC.3 COMPACT TWO-ELEMENT RECONFIGURABLE ANTENNA
SYSTEM FOR THE 470-702 MHZ BAND
This
paper presents a miniature reconfigurable dual-antenna system addressing the
UHF band. This system has been introduced for small mobile terminals, where
form factor is very important. The whole structure respects some design rules
in order to optimize antenna performances from diversity performances point of
view. A specific active capacitive load has allowed the impedance
reconfigurability and antennas miniaturization. Antenna miniaturization is used
to combine radiating structures in an electrically small volume. The use of two
antennas could bring good diversity gain to mitigate the fast fading effect
introduced by multipath in mobility.
14:40 DBC.4 PERFORMANCE EVALUATION OF A RECONFIGURABLE
MULTIMODE PIXELED ANTENNA IN INDOOR CLUSTERED MIMO CHANNELS
This
paper investigates the performance evaluation of a reconfigurable multimode
pixeled antenna in wireless communication systems employing antenna
pattern/polarization diversity techniques. Simulations have been conducted
using an indoor clustered MIMO channel model.
15:00 DBC.5 PERFORMANCE ASSESSMENT OF BI-SCALAR
BEAMFORMERS IN PRACTICAL PHASED ARRAY FEED SYSTEMS
We
assess the sensitivity and polarimetric performance of a phased array feed
(PAF) system in which the two sets of nominally orthogonally polarized elements
are beamformed separately. Out simulations of an actual PAF system indicate
that such bi-scalar instead of full-polarimetric beamforming results in about
4% sensitivity loss and an XPD of about 45 dB. Our measurements confirm the
sensitivity loss, but indicate worse polarimetric performance than the
simulations. We indicate how the performance of a PAF system with bi-scalar
beamforming can be improved by beamforming the cross-polarization signals and
polarimetric corrections to the beamformer outputs.
15:20 DBC.6 ON ANTENNAS FOR COGNITIVE RADIOS
Cognitive
Radios (CR) are a concept of radios endowed with an intelligence that allows
them to perceive changes in their environment and adapt their parameters to
maintain a quality of Service (QoS). While the parameters concerned by the
adaptation enclose theoretically all of those of a radio (modulation, coding,
...etc.), it is certainly the change of the operating frequency that is the
most characteristic of CR. In light of this new requirement, the present paper
analyzes the features that CR antennas can have. Then, examples of frequency
reconfigurable antennas developed by our group for CR will be presented.
15:40 End of the Session
EGH – Terrestrial and Planetary Electromagnetics
Session Chairs: Masashi Hayakawa, Yurdanur Tulunay, Colin Price
Session EGH
Type Oral Presentation
Schedule Tuesday, August 16, 13:40-15:40
Room Galata
13:40 EGH.1 OVERVIEW OF ELECTROMAGNETIC WAVES DUE TO
THUNDERSTORM ACTIVITY AND OBSERVED BY DEMETER
M. Parrot, LPC2E/CNRS, Orleans, France
DEMETER
is a low orbiting satellite (660 km) which recorded wave and plasma parameters
all around the Earth (except in the auroral zones) at two different local times
(10.30 and 22.30 LT). This paper will present the emissions observed in
relation with the thunderstorm activity. Many different phenomena have been
registred. It includes: - various whistlers, - particle precipitation by
whistlers, - interaction with the lower hybrid frequency, - observations of MF
pulses, - interaction between thunderstorm activity and man-made activity, -
triggered emissions by whistlers, and - emissions observed at the time of very
powerful lightning strokes
14:00 EGH.2 DETERMINATION OF THE IONOSPHERIC
TRANSMISSION LOSS OF THE LOW FREQUENCY EM WAVES BY SIMULTANEOUS MEASUREMENTS OF
SATELLITE AND GROUND-BASED EXPERIMENTS
The
ionospheric transmission loss has been obtained for different latitudes and
local times by comparing the Poynting flux at the lightning source by the
ground-based ELF transient measurements with lightning whistlers above the
ionosphere observed by DEMETER satellite. As a result, the ionospheric
penetration loss increases with decreasing the magnetic latitude and with
increasing wave frequency. The penetration loss is much larger in daytime rather
than night time. The experimentally obtained results are in good agreement with
those from theoretical calculations.
14:20 EGH.3 ELF Q-BURST CAUSED BY EXTRAGALACTIC GAMMA
RAY BURST
Experimental
results are presented on electromagnetic pulse associated with the abrupt
change in the Earthionosphere cavity caused by the intense gamma ray burst of
December 27, 2004. Parameters of observed extremely low frequency pulse
correspond to expectations: the source bearing points to the epicenter of ionosphere
modification, the waveform is similar to that computed, its amplitude exceeds
by a few times the level of regular Schumann resonance background. The ELF
pulse onset at the Karymshino observatory (52.8 N, 158.3 E) is ~0.16 s prior to
the published time of modification in the VLF records.
14:40 EGH.4 A.C./D.C. ATMOSPHERIC GLOBAL ELECTRIC
CIRCUIT PHENOMENA
We
review the global circuit driven by thunderstorms and electrified rain clouds.
With the ionosphere at an equipotential of ~ +250 kV with respect to the Earth,
the load in the circuit is the fair weather atmosphere; its conductivity is
mainly determined by the flux of galactic cosmic rays. The circuit exhibits
variability in both space and time by more than fifteen orders of magnitude. We
discuss results produced by a new electrical engineering analogue model of the
circuit constructed using the PSpice software package. Finally, we consider
several interesting new experimental observations relating to the topic.
15:00 EGH.5 A VHF BROADBAND INTERFEROMETER FOR
LIGHTNING OBSERVATION
A
VHF broadband interferometer is a system to locate sources of the radiation
events at VHF band by extracting the differences of phases at various frequency
components of Fourier spectra between a pair of antennas. Lightning images are
derived by sensing the electromagnetic waves from lightning discharge process
such as negative stepped leader. Using the system, lightning observations have
been carried out firstly for rocket triggered lightning experiment, then, in
Darwin Australia, and so on. Based on the successful results, the
interferometer system is deployed on the ISS to detect and locate the VHF
impulses emitted by lightning from space.
15:20 EGH.6 SEISMOGENIC ULF MAGNETIC ACTIVITY -
PECULIARITIES OF REGISTRATION
V. Korepanov, F. Dudkin, Lviv Centre of Institute for Space Research, Lviv, Ukraine
A
big number of publications confirm that ultra low frequency (ULF) magnetic
precursors were recorded from few weeks up to few hours before earthquakes
(EQs). For the detection of magnetic precursors at the background of more
powerful sources it is necessary to have magnetic field sensors with wide
dynamics and minimum possible spectral noise density. The newly developed
technology of EQ-related ULF signals selection is presented. The attempts of
this technology application in order to select the candidates for EQ precursors
are discussed, basing on the natural ULF signals, collected in India by
multi-point synchronized magnetometer network.
15:40 End of the Session
F04 – Active and Passive Remote Sensing of Vegetation (in honor of Roger H. Lang)
Session Chairs: Simonetta Paloscia, Martti Hallikainen
Session F04
Type Oral Presentation
Schedule Tuesday, August 16, 13:40-15:40
Room Haliç
13:40 F04.1 REMOTE SENSING OF SALINITY: THE DIELECTRIC
CONSTANT OF SEA WATER
Global
monitoring of sea surface salinity from space requires an accurate model for
the dielectric constant of sea water as a function of salinity and temperature
to characterize the emissivity of the surface. Measurements are being made at
1.413 GHz, the center frequency of the Aquarius radiometers, using a resonant
cavity and the perturbation method. The cavity is operated in transmission mode
and immersed in a liquid bath to control temperature. Multiple measurements are
made at each temperature and salinity. Error budgets indicate a relative
accuracy for both real and imaginary parts of the dielectric constant of about
1%.
14:00 F04.2 EM DISCRETE APPROACH FOR RAINFALL
ATTENUATION OF PROPAGATION
S. S. Seker, A. Y. Citkaya, Bogazici University, Istanbul, Turkey
Electromagnetic
propagation through sparse distribution of lossy dielectric particles in a rain
is investigated. Mathematical model is developed to aid in the interpretation
of the interactions data obtained by electromagnetic remote probing of rain.
Attenuation is computed, for waves passing through raindrops specified size,
shape and distributions. Computer simulation which is based on the model
proposed with different shapes was compared with the experimental data, and
excellent agreement was obtained.
14:20 F04.3 POTENTIALS OF X-BAND ACTIVE AND PASSIVE
MICROWAVE SENSORS IN MONITORING VEGETATION BIOMASS
In
this paper the potentials of both emissivity and backscatter at X-band for the
monitoring of plant parameters are investigated and the interrelations between
these two quantities are discussed. Remote sensing data collected in agricultural
surfaces and for different crop types in Italy have been analyzed and compared
with vegetation parameters (mainly plant water content and leaf area index)
measured on ground . A discrete element radiative transfer model tuned for both
active and passive cases was used to perform a sensitivity analysis. A direct
comparison of measured emissivity and backscattering is carried out.
14:40 F04.4 BACKSCATTER MEASUREMENTS OVER VEGETATION
BY GROUND-BASED MICROWAVE RADARS
M. Kurum, P. O'Neill, NASA Goddard Space Flight Center, Greenbelt, MD, United States
In
the study of radar backscattering from vegetated terrain, it is important to
understand how the electromagnetic wave interacts with vegetation and
underlying ground. In this paper, an expression of backscattering from a
vegetation canopy in the case of spherical wave illumination is derived. Such
an expression might apply to the practical case of a ground-based scatterometer
overlooking vegetation. The relative importance of the beamwidth as well as
platform height on backscattering from vegetated terrain is studied.
Preliminary results indicate that the discrepancy with plane wave illumination
can be rather significant, and therefore should not be overlooked.
15:00 F04.5 CALCULATION OF THE DOUBLE SCATTERING FROM
LOSSY DIELECTRIC CYLINDERS
Q. Zhao, R. H. Lang, The George Washington University, Washington,DC, United States
A
numerical Fresnel Double Scattering (FDS) method is presented in this paper to
accurately calculate the bistatic cross sections due to double scattering
between two lossy dielectric cylinders in the Fresnel zone of each other. The
cylinders have a comparable size to the wavelength for L band frequencies. It
is demonstrated that the FDS results reduce to the far field results when the
scatterers are sufficiently far apart. The FDS method can be employed to study
the double scattering effects between tree branches in microwave forest
scattering models.
15:20 F04.6 COHERENCE EFFECTS IN L-BAND ACTIVE AND
PASSIVE REMOTE SENSING OF QUASI-PERIODIC CORN CANOPIES
Due
to their highly random nature, vegetation canopies can be modeled using the
incoherent transport theory for active and passive remote sensing applications.
Agricultural vegetation canopies however are generally more structured than
natural vegetation. The inherent row structure in agricultural canopies induces
coherence effects disregarded by the transport theory. The objective of this study
is to demonstrate, via Monte-Carlo simulations, these coherence effects on
L-band scattering and thermal emission from corn canopies consisting of only
stalks.
15:40 End of the Session
G04 – Practical Applications and Techniques for the Use of Ionosonde Data
Session Chairs: Paul Cannon, Lee-Anne McKinnell
Session G04
Type Oral Presentation
Schedule Tuesday, August 16, 13:40-15:40
Room Topkapi A
13:40 G04.1 PRINCIPLES OF DYNASONDE NAVIGATOR
Dynasonde
is an ideology of precision ionospheric radio sounding based on rigorously
taking into account phase characteristics of a radio echo. Unique products of
phase ionosondes intended for various Space Weather-related applications
include: echo recognition and noise discrimination, echo classification into
traces, scaling of standard ionospheric parameters, 3-D plasma density
inversion (NeXtYZ) including true vertical profile with error bars, small-scale
irregularity diagnostics, and vector velocities, all obtained autonomously from
ionogram data. Our report describes details of implementation of Dynasonde
principles in operation of the web portal Dynasonde Navigator
(http://dynserv.eiscat.uit.no) hosted by EISCAT.
14:00 G04.2 GLOBAL IONOSPHERIC RADIO OBSERVATORY
(GIRO): STATUS AND PROSPECTIVE
The
Global Ionospheric Radio Observatory (GIRO), http://giro.uml.edu, acquires and
disseminates HF ionospheric sounding data from 64 Digisonde locations in 27
countries. GIRO publishes its 30+ million record holdings over Internet,
provides interactive environment to data interpretation experts, and forwards
real-time data for assimilation and forecast of radiowave propagation and space
weather. Of importance to the ionospheric community are the long-term holdings
of manually validated electron density profiles for modeling, studies of the
autoscaling uncertainty, and validation of alternative measurement techniques.
Real-time GIRO feeds will be used to build an assimilative International
Reference Ionosphere model.
14:20 G04.3 HIGH PERFORMANCE IONOSPHERIC SOUNDING
T. W. Bullett, University of Colorado, Boulder, CO, United States
The
application of digital receivers, digital signal processing and other advanced
electronics and antenna technologies have become sufficiently mature and cost
effective to be implemented into High Frequency radars for ionospheric
sounding. When these technologies are used to improve the performance of the HF
radar, new observational modes with greater resolution, sensitivity and
precision are possible, which allow for discovery, research and renewed
investigation of the ionosphere. This paper presents unique data from high
performance ionosondes.
14:40 G04.4 THE SOUTH AFRICAN IONOSONDE NETWORK: PAST
AND PRESENT
The
South African ionosonde network has played an extensive role in African Space
Physics studies since 1973, and continues to do so with a four ionosonde site
network. This paper will describe the growth of this network, and the various
practical projects that the network has been involved in, and indeed, made
possible over the past decade. Future planned projects will also be discussed,
and will include endeavors to grow the network into Africa. In addition, the
South African ionospheric map will be used as an example of successful practical
applications for the data collected from this network.
15:00 G04.5 ON THE USE OF IONOSONDE PROFILES IN THE
ELECTRON DENSITY ASSIMILATIVE MODEL (EDAM)
The
Electron Density Assimilative Model (EDAM) assimilates disparate ionospheric
measurements into a background ionospheric model in order to produce 3D
representations of ionospheric electron density. Previous tests using EDAM and
ground based slant total electron content data have demonstrated that this type
of data contains limited information on the vertical structure of the
ionosphere. By assimilating data from ionosondes into the model, information
regarding the profile peak below the F2 layer can be obtained. This paper
describes an assimilation test scenario in the Republic of South Africa and
reports on the benefits of including ionosonde data in EDAM.
15:20 G04.6 THE PROJECT OF MONITORING THE IONOSPHERE
OVER RUSSIAN FEDERATION BY MEANS OF DIGITAL FMCW IONOSONDES NETWORK
For monitoring the current ionospheric conditions over
Russian Federation area in quasi real-time we offer to use modern digital FMCW
vertical incidence ionospheric stations capable to receive oblique incidence
signals during vertical sounding session. Newness of such ionospheric network
consists in combining capabilities of vertical incidence and oblique incidence
ionosondes. It becomes possible because of operative technique for
reconstruction ionospheric parameters at path midpoint and appearance of modern
digital multichannel receivers which were examined by few continuous
experimental works in Russian Federation.
15:40 End of the Session
HT – Major developments in our understanding of electric antennas in space plasmas
Session Chair: Yoshiharu Omura
Session HT
Type Oral Presentation
Schedule Tuesday, August 16, 13:40-14:40
Room Topkapi B
13:40 HT.1 MAJOR DEVELOPMENTS IN OUR UNDERSTANDING OF
ELECTRIC ANTENNAS IN SPACE PLASMAS
G. James, Communications Research Centre Canada, Ottawa, Canada
Salient
points in the history of the science of dipoles as an important part of space
radio science methodology are reviewed. From its earliest days, the study of
spontaneous radio emissions of geospace has required accurate measurements of
wave electric fields. This review starts with the work done early in the space
age on distributed dipole behaviour in cold magnetoplasmas. Evidence of the
effects of hot-plasma wave modes and of the response of space plasma excited by
active antennas led to a broadening of the dipole theory to include the
generation and detection of electrostatic waves. The observations of plasma
nonlinearities during the operation of active dipoles required further
explanation. Indications of nonlinearity included spectra implying parametric
processes and the RF- pumping of ambient ions and electrons, both in the dipole
near fields. The challenge today of understanding the inherent complexity of
dipoles in magnetoplasmas may be met by recourse to particle-in-cell methods to
predict classic antenna properties such as impedance, radiated field or
effective length.
14:40 End of the Session
J04 – Space and Moon-based radio astronomy: science and technology
Session Chair: Leonid Gurvits
Session J04
Type Oral Presentation
Schedule Tuesday, August 16, 13:40-15:40
Room Marmara
13:40 J04.1 THE PLANCK MISSION
H.-U. Norgaard-Nielsen, Danish Space Research Institute, Copenhagen, Denmark
Planck
is an astronomical satellite part of the Scientific Programme of the European
Space Agency, which is designed to image the anisotropies of the Cosmic
Microwave Background (CMB) over the whole sky, with unprecedented sensitivity
and angular resolution. Planck was launched together with Herschel on 14 May
2009. By August 2011, it will have completed almost three full sky surveys. In
January 2011 the first data products and scientific results were released to
the public. I will present an overview of the Planck mission, its scientific
objectives, the key elements of its technical design, current status, and first
scientific results
14:00 J04.2 SPACE-BASED ULTRA-LONG WAVELENGTH RADIO
ASTRONOMY AN OVERVIEW OF TODAYS INITIATIVES
Space
based ultra-long wavelength radio astronomy has recently gained interest. The
need for large effective apertures spread over long ranges implies that
advanced technologies are required, which is in reach at this moment. This
together with the unexplored frequency band below 30 MHz makes these
initiatives very interesting. Due to a combination of ionospheric scintillation
below ~30MHz, its opaqueness below ~10MHz, and man-made RFI, earth-bound radio
astronomy observations are either severely limited in sensitivity and spatial
resolution or entirely impossible. In this paper we will present current
initiatives to reach this new and unexplored low frequency band.
14:20 J04.3 STATUS AND MAIN PARAMETERS OF THE SPACE
VLBI MISSION RADIOASTRON
M. Popov, Astro Space Center of the Lebedev Physicxal institute, Moscow, Russian Federation
The
RadioAstron project is an international collaborative mission to launch a
free-flying satellite carrying a 10-m space radio telescope (SRT) into an
elliptical orbit around the Earth. The aim of the mission is to use the space
telescope for radio astronomical observations using VLBI (Very Long Baseline
Interferometry) techniques in conjunction with ground-based VLBI networks. We
explain basic parameters of the on-board scientific equipment as was measured
during the final tests. Peculiarities of RadioAstron moon-perturbed orbit will
be discussed. We will describe satellite operations, experiment scheduling, and
science access to the mission
14:40 J04.4 PRECISION RADIO SCIENCE FOR PLANETARY
GRAVITY, ATMOSPHERIC AND SURFACE INVESTIGATIONS
S. Asmar, Jet Propulsion Laboratory, Pasadena, CA, United States
Radio
Science techniques, microwave links between spacecraft and ground stations,
have produced numerous discoveries. SNR and geometrical limitations require new
instrumentation such as spacecraft-spacecraft links that require special
open-loop receiver. One is on GRACE/GRAIL for gravitational measurements;
another onboard New Horizons for uplink occultation. One on MRO demonstrated
the method with Odyssey. A new receiver designed to meet Radio Science
requirements has been prototyped for the Europa and Ganymede orbiters
scientific objectives of occultations of the atmosphere and ionosphere of
Jupiter and its satellites, as well as the rings, and bistatic scattering from
surfaces of the satellites.
15:00 J04.5 INTRODUCTION OF PROMOTING VERY LONG
BASELINE INTERFEROMETRY FOR DEEP SPACE TRACKING IN CHINA
J. Ping, Shanghai Astronomical Observatory, CAS, Shanghai, China
VLBI
has been developed in China near 30 years. Since 2003, the astronomical VLBI
technique was adapted for tracking and orbiting the Chinese ChangE 1 & 2
missions, and played important role on positioning the orbit injection and hard
landing. Since 2007, the concepts of open loop Doppler, DOR and DOD have been
accepted by Chinese VLBI system for Martian missions. In the near future, same
beam VLBI technique will also be applied by this system for tracking dual
Martian mission Phbos-Grunt and Yinghuo-1, as well as positioning the
ChangE-3/4 landers & rovers.
15:20 J04.6 VLBI TRACKING OF THE SOLAR SAIL MISSION
IKAROS
H. Takeuchi, ISAS/JAXA, Sagamihara, Japan
IKAROS
is the world's first solar sail spacecraft which was launched in 2010. To
determine the orbit under the continuous big influence of solar radiation
pressure, VLBI observation is effective because sky plane position of the
spacecraft can be directly determined by VLBI observables without a priori
assumption for solar radiation pressure model. In order to effectively perform
VLBI measurements, Delta-DOR multi-tone generator was installed to the
spacecraft. A total number of 24 VLBI experiments among 8 agencies were
performed during July and August in 2010. Data processing algorithm and initial
results of orbit determination are presented.
15:40 End of the Session
H04 – Wave-particle Interactions and Their Effects on Planetary Radiation Belts II
Session Chairs: Jacob Bortnik, Craig Rodger, Bruce Tsurutani, Richard Horne
Session H04
Type Oral Presentation
Schedule Tuesday, August 16, 14:40-15:40
Room Topkapi B
14:40 H04.1 CONJUGATE STUDIES OF WHISTLER-MODE WAVES
IN THE VAN ALLEN RADIATION BELTS
Whistler-mode
waves, especially chorus, can influence energetic electrons in the Van Allen
radiation belts. These electromagnetic waves propagate over long distances in
the magnetosphere. It has been previously shown that chorus can propagate from
its equatorial source down to the subauroral ionosphere. We investigate cases
where whistler-mode waves were simultaneously measured by the Cluster
spacecraft in the magnetosphere and by the low-orbiting Demeter spacecraft.
Multicomponent measurements of both these spacecraft missions allow us to
investigate the wave-vector directions and Poynting flux. We can therefore show
conjugate propagation properties of the waves in two different magnetospheric
regions.
15:00 H04.2 DETECTION OF MAGNETOSPHERICALLY DUCTED VLF
SIGNALS GEOMAGNETICALLY CONJUGATE TO A RUSSIAN ALPHA TRANSMITTER AT L=1.9
The
Russian 'Alpha' transmitters broadcast alternating pulses between 11-15 kHz for
navigation. A fraction of the VLF energy escapes into the magnetosphere, is
guided by ducts, amplified by interaction with radiation belt particles, and
observed at the geomagnetic conjugate point. We analyze VLF data from Adelaide,
Australia, conjugate to Komsomolsk transmitter. An automated detection scheme
separates the subionospheric and magnetospheric signals. We track availability
of ducts at L=1.9 and find them present often. We correlate to geomagnetic
conditions and assess the role of wave growth and triggering from wave-particle
interactions, and compare to DEMETER satellite measurements.
15:20 H04.3 ELECTROMAGNETIC WAVES OBSERVED BY DEMETER
DURING SUSTAINED MAGNETIC ACTIVITY
M. Parrot, LPC2E/CNRS, Orleans, France
DEMETER
is a low polar orbiting satellite (660 km) which was operating for more than
six years. This paper will present an overview of the electromagnetic waves
observed during sustained magnetic activity, and then enhanced by a
wave-particle interaction. It includes: - waves such as hiss, chorus, QP (Quasi
Periodic) emissions, triggered emissions, EMIC (ElectroMagnetic Ion Cyclotron)
waves in the equatorial region, - emissions at the lower hybrid frequency, -
man-made waves such as PLHR (Power Line Harmonic Radiation) and MLR
(Magnetospheric Line Radiation), and - specific waves recorded during very
intense magnetic activities or in particular regions (SAA, sub-auroral zones).
15:40 End of the Session
Session Chair: William Davis
Session AB1
Type Oral Presentation
Schedule Wednesday, August 17, 08:00-10:40
Room Dolmabahçe C
08:00 AB1.1 TOWARD ACCURATE ANTENNA MEASUREMENTS USING
MULTI-PROBE SYSTEMS
A
few important aspects related to spherical multi-probe antenna measurements and
their future research and development needs are discussed. In particular, the
significance of the test zone field compensation technique as an enabler for
accurate antenna measurements with multi-probe systems is addressed.
08:20 AB1.2 RAPID MILLIMETER-WAVE ANTENNA MEASUREMENTS
USING A NOVEL TABLE-TOP BIPOLAR PLANAR NEAR-FIELD TECHNIQUE
Bipolar
planar antenna measurements have been used as an alternative to other planar
scanning techniques such as plane-rectangular or plane-polar scanning. Bipolar
scanning features important advantages such as the elimination of linear motion
in measurement, increased stability, compact footprint, and a variety of data
acquisition modes. These advantages mitigate many of the issues of measuring
small antennas operating at millimeter-wave frequencies. This paper describes
and elaborate on the advantages of the bipolar scanner for millimeter-wave
antenna measurement, including at introduction of new scanning modes that can
help dramatically reduce measurement time over previously implemented scanning
modes.
08:40 AB1.3 DESIGN AND REALIZATION OF A PLANAR NEAR
FIELD ANTENNA MEASUREMENT SYSTEM
Radiation
pattern measurement is one of the major issues in antenna characterization.
This measurement is performed in the far field range, which can be several tens
of meters for the case of directive antennas. Near field approach renders these
measurements possible inside a small laboratory. Nevertheless, since the design
and the realization of near field antenna measurement systems require detailed
engineering, they are fairly expensive. For obtaining a low-cost, maintainable
and native near field antenna measurement system, an engineering activity was
conducted and a near field measurement system was developed. Here we present
antenna patterns measured by this system.
09:00 AB1.4 A DIRECT MATRIX APPROACH TO 3-D ANTENNA
RADIATION-PATTERN ESTIMATION FROM PARTIALLY-SCANNED SPHERICAL NEAR-FIELD DATA
T. Yang, W. A. Davis, Virginia Tech, Blacksburg, VA, United States
Far-field
radiation-pattern estimation is explored for partially-scanned, spherical
near-field data resulting from physical limitations of antenna under test or
associated measurement systems. A direct matrix approach, based on
spherical-wave expansions, is found to be simple and effective for constructing
the 3D pattern from partially-scanned near-field data. Criteria on the minimum
near-field data for full 3D pattern reconstruction is explained. The concept of
the direct matrix approach is demonstrated for mobile and horn antennas. A
reduction of the scan time is an added benefit of this antenna measurement
method.
09:20 Tea/Coffee Break
09:40 AB1.5 THE ENGINEERING IMPLEMENT OF ANTENNA
TIME-DOMAIN NEAR-FIELD MEASUREMENT SYSTEM
B. Cui, Z. Xue, N. Wang, W. Ren, W. Li, X. Xu, Beijing Institute of Technology, Beijing, China
At
present, a complete measurement system has been built up successfully by our
laboratory, besides its engineering implement has been accomplished also. We
can show an antennas radiation field in a form of 3D animation dynamically with
this measurement system, which demonstrates the time-domain near-field
measurement theory and the time-domain near-field measurement system are
practical. The present paper will introduce the basic principles, the
components of the system and the essential techniques. The screenshots of the
dynamic 3D animation will be shown in the part of conclusion at last.
10:00 AB1.6 AN INNOVATIVE AND EFFICIENT METHOD TO
MEASURE SMALL ANTENNAS IN WATER CONDUITS
D. Trinchero, R. Stefanelli, Politecnico di Torino, Turin, Italy
Wireless
Sensor Networks have been recently proposed for applications in many systems.
Among all, the possibility to insert a node inside a liquid has attracted
attention by few authors. The paper presents the design and construction of a
test bench for experimental characterization of antennas inside liquids. The
design has involved the classification of a large variety of pipelines, among
which three different samples have been selected. The pipeline has consequently
been configured in order to host fixed or mobile antennas, which can be wired
towards the external part of the conduit, to facilitate their connection to a
network analyzer.
10:20 AB1.7 A MODIFIED VERSION OF THE RADIATION
PATTERN INTEGRATION METHOD FOR THE MEASUREMENTS OF THE RADIATION EFFICIENCY OF
ELECTRICALLY SMALL MAGNETIC ANTENNAS
R. Stefanelli, D. Trinchero, Politecnico di Torino, Turin, Italy
The
radiation efficiency of an antenna is always critical to characterize
experimentally. In this paper four methods are reviewed and analyzed: the
Wheeler method, Q method, radiometric method and radiation pattern integration
method. Among them, a modified version of the last is introduced, in order to
obtain a more efficient and faster measurement procedure, applicable to the
characterization of small magnetic antennas. The simulation results demonstrate
that using this method an improvement of 70% of the time and calculation effort
can be reached. Nevertheless, the method introduces an acceptable uncertainty,
never larger than 0.5 dB.
10:40 End of the Session
B06 – Multiscale Modeling and Applications to Composite Materials
Session Chairs: Niklas Wellander, Daniel Sjoberg
Session B06
Type Oral Presentation
Schedule Wednesday, August 17, 08:00-10:40
Room Anadolu Auditorium
08:00 B06.1 ANTI-RESONANT RESPONSE OF RESONANT
INCLUSIONS?
When
retrieving the material parameters of a metamaterial with resonant inclusions,
the expected Lorentz-like resonance in one parameter typically yields an
unexpected and unphysical so-called antiresonance in the other effective
parameter. Using a simple model problem with plasmonic cylinders, we discuss
some explanations for the antiresonance-problem and argue that the fundamental
reason is that the assumed homogeneous model with sharp boundaries is
insufficient when the retrieval fails to produce physically reasonable results.
Some promising paths towards a better model are also briefly discussed.
08:20 B06.2 CHARACTERIZATION OF THE OPTICAL MODES IN
3D-PERIODIC ARRAYS OF METALLIC NANOSPHERES
Complex
optical modes in 3D-periodic arrays of metallic nanospheres are analyzed at
optical frequencies for both longitudinal and transversal (with respect to the
mode traveling direction) polarization states. Each nanosphere is modeled to
act as a single dipole by using the single dipole approximation approach, and
the metal permittivity is described by the Drude model. Complex mode dispersion
diagrams, the figure of merit and effective refractive index versus frequency
are shown and compared with those obtained with Maxwell Garnett homogenization
theory. Comparison with effective permittivity retrieved by scattering
parameters of finite-thickness structures will be shown during the
presentation.
08:40 B06.3 HOMOGENIZATION OF A NONLOCAL ELECTROSTATIC
EQUATION
We
find the effective (homogenized) properties of a composite (a heterogeneous
material) supplied with spatially non-local constitutive relations. We homogenize
an electrostatic equation in a periodic setting. The current density is given
as a spatial convolution of the electric field with a conductivity kernel. It
turns out that the homogenized equation also has a nonlocal constitutive
relation if we do not scale the non-localness. However, if we decrease the
neighborhood which influence the current density simultaneously as we make the
fine structure scale finer and finer then we obtain a constitutive relation
which is local.
09:00 B06.4 TRANSFORMATION MEDIA FOR FINITE ELEMENT
SOLUTION OF MULTI-SCALE ELECTROMAGNETIC BOUNDARY VALUE PROBLEMS
We
present coordinate transformation techniques for solving multi-scale
electromagnetic boundary value problems involving fine geometrical features.
The purpose is to eliminate fine mesh and to allow uniform and easy-to-generate
meshes in the finite element solution of multi-scale problems by introducing
metamaterial regions into the computational domain. The approaches are based on
the form-invariance property of Maxwells equations. The medium where the coordinate
transformation is applied is equivalent to an anisotropic medium whose
constitutive parameters are determined by the Jacobian of the transformation.
Several numerical simulations are illustrated in the context of electromagnetic
scattering problems.
09:20 Tea/Coffee Break
09:40 B06.5 SCATTERING MEASUREMENTS IN A PARALLEL
PLATE WAVEGUIDE - FIRST RESULTS
This
paper describes a parallel plate waveguide for scattering and material
measurements. The setup can for certain scatterers be considered as a 2D radar
cross section (RCS) range. Measurements on metallic circular cylinders are
performed, and the forward RCS and the extinction cross section are determined.
Two different calibration methods are used, and it is found that the method
employing a calibration object is the most accurate. It is concluded that the
2D RCS in the forward direction can be measured with +-1 dB accuracy at the 10
cm level and with +-3 dB accuracy at the 1 cm level.
10:00 B06.6 ELECTRIC AND MAGNETIC FIELD DYADIC GREENS
FUNCTIONS AND DEPOLARIZING DYAD FOR A MAGNETIC CURRENT IMMERSED IN A UNIAXIAL
DIELECTRIC-FILLED PARALLEL PLATE WAVEGUIDE
M. J. Havrilla, Air Force Institute of Technology, WPAFB, OH, United States
The
principal and reflected electric and magnetic field dyadic Greens functions for
a magnetically-excited PEC parallel-plate waveguide filled with a uniaxial
dielectric are derived. It is shown that the source maintains TEz and TMz field
sets that don't couple at the PEC boundaries. A relatively simple formulation
for computing the magnetic field Greens function is developed. A Leibnitz rule
methodology for computing the depolarizing dyad is also presented, resulting in
Greens functions that are valid outside and inside the source region. Future
research involving these Greens functions in characterizing uniaxial materials
is discussed.
10:20 B06.7 ACHERS CONSTRAINT ON THE HIGH-FREQUENCY
MAGNETIC PERFORMANCE OF COMPOSITES
K. N. Rozanov, ITAE, Moscow, Russian Federation
The
paper generalizes the results available from the literature on the constraint
on the high-frequency permeability of magnetic composites, with the stress made
on the opportunities for obtaining of materials with high microwave
permeability. The rigorous derivation is presented of the integral constraint
on the permeability. A simple estimation of the effect of eddy currents is
given. The applicability limits and opportunities to over-come the constraint
are discussed. That the constraint is believed to be invalid in flake particles
with hard mag-netic axis perpendicular to the flake plane and in tiny magnetic
particles possessing exchange resonance modes.
10:40 End of the Session
CBD – Vehicular Communications
Session Chair: Alain Sibille
Session CBD
Type Oral Presentation
Schedule Wednesday, August 17, 08:00-09:20
Room Dolmabahçe A
08:00 CBD.1 PERFORMANCE ANALYSIS OF VEHICLE-TO-VEHICLE
TUNNEL MEASUREMENTS AT 5.9 GHZ
In
this contribution, we discuss and analyze results from real-world performance
measurements for IEEE 802.11p along motorway A22 near Vienna, Austria. More
specifically, we evaluate the frame success ratio and goodput of the IEEE
802.11p physical layer for a vehicle-to-vehicle scenario in a tunnel. We report
and discuss the observed frame success ratios and goodputs for radio channels
between the transmit and the receive antenna with and without a line-of-sight
component, and investigate the impact of the propagation environment and the
traffic situation inside the tunnel.
08:20 CBD.2 ADAPTIVE MIMO ALGORITHMS FOR
TRAIN-TO-WAYSIDE TRANSMISSIONS IN TUNNELS
This
paper presents enhancements of train-to-wayside transmission systems, based on
MIMO with and without channel state information at transmitter to increase
performance without increasing the number of modems and power. The channel in
tunnel with a masking train is modeled with the Kronecker model obtained with a
3D ray tracing tool. The MIMO schemes considered are: SM, STBC, max-dmin and
P-OSM at 5.8 GHz with a targeted Frame Error Rate of 3.10-2 for a frame length
of 100 bytes. They are compared in terms of signal to noise ratio (SNR) versus
spectral efficiency.
08:40 CBD.3 DISTRIBUTED MIMO INTERFERENCE ALIGNMENT IN
PRACTICAL WIRELESS SYSTEMS
G. W. K. Colman, T. J. Willink, Communications Research Centre Canada, Ottawa, Ontario, Canada
In
order for interference alignment (IA) techniques to be implemented in future
generation mobile multiple-input multiple-output (MIMO) communications systems,
they must be shown to be robust to system limitations such as quantisation and
delay. Current IA algorithms in the literature assume global and instantaneous
channel knowledge. In this paper, a novel IA algorithm is proposed which uses
limited feedback and local channel information. Simulations using realistic
channel models show that this algorithm can provide viable communications in
the overloaded MIMO interference channel.
09:00 End of the Session
Session Chairs: Frédérique de Fornel, Nader Engheta
Session DB2
Type Oral Presentation
Schedule Wednesday, August 17, 08:00-10:40
Room Dolmabahçe B
08:00 DB2.1 NANOPLASMONICS: NEW DESIGN CONCEPTS FOR
NANOSCALE OPTICAL CAVITIES
A. Fernandez Dominguez, S. A. Maier, Imperial College London, London, United Kingdom
The
design of nanoplasmonic cavities exploiting coherent processes such as sub- and
superradiance as well as Fano-type interactions will be discussed. In such
cavities, interactions between bright and dark localized plasmon modes lead to
a complex mode spectrum, which can be visualized using electron energy loss
spectroscopy. First implementations fabricated using electron beam lithography
will be presented. Furthermore, it will be shown how the concept of
transformation optics can be utilized for the design of nanoresonators with a
broadband absorption spectrum, showing high promise for light harvesting over
the whole visible and infrared range of the spectrum.
A. V. Zayats, King's College London, London, United Kingdom
We
will discuss various plasmonic approaches for controlling photonic signals on
subwavelength scales. Plasmonic crystals, plasmonic waveguiding components as
well a new plasmonic platform based on metamaterials will be presented. Particular
emphasis will be given to achieving active functionalities using various
control stimuli such as electronic and magnetic fields and all-optically.
Amplification of plasmonic signals and dispersion management will also be
addressed. Active and tuneable plasmonic components are required for
development of integrated photonic circuits, in high-density data storage as
well as bio- and chemo-sensing lab-on-a-chip systems, to name a few.
08:40 DB2.3 NONLINEAR PLASMONICS
F. Capasso, Harvard University, Cambridge, MA, United States
Surface
Plasmon Polaritons (SSPs) can achieve concentration of light into
sub-wavelength regions thus opening up rich new directions in physical optics
and photonics. We present experiments on plasmonic nanocavities patterned on the
surface of metals and semiconductors and designed to concentrate light in
nanoscale volumes. This has led us to the observation of large enhancements of
nonlinear optical phenomena such as four wave mixing in gold.
09:00 DB2.4 CONTROLLING SINGLE-MOLECULE EMISSION WITH DIELECTRIC AND PLASMONIC ANTENNAS
V. Sandoghdar, Max Planck Institute for the Science of Light, Erlangen, Germany
Modification
of the radiative properties of atoms has been an exciting topic of research in
quantum optics for about three decades. While the usual approaches to this
problem have used microcavities for molding the available modes, more recent
developments have exploited the concept of antennas in the near field. In this
talk, I will give a brief overview of our theoretical and experimental
achievements in inducing directed emission by single molecules and enhancing
their spontaneous emission rates. We will also discuss future prospects of this
line of research and its applications
09:20 Tea/Coffee Break
09:40 DB2.5 DIAMOND NANOPARTICLES AS SURFACE-PLASMON
LAUNCHERS: TOWARDS A DETERMINISTIC QUANTUM PLASMONICS
S. Huant, A. Cuche, O. Mollet, A. Drezet, Institut Neel/ CNRS & UJF Grenoble, Grenoble, France
A
nanodiamond hosting two NV centers is attached to the apex of an optical
fiber-tip and illuminated by a laser light guided by the fiber itself. Gold
films are dipped into the optical near field of this tip. The fluorescence
light generated by the NVs launches surface plasmons that are imaged by
near-field microscopy. Since the nanodiamond is a quasi single-photon source,
we argue that single surface plasmons form the experimental images. This is a
first step towards a deterministic quantum plasmonics where quantum plasmons
can be launched at any freely chosen position in a plasmonic receptacle.
10:00 DB2.6 INTEGRATED PLASMONIC SYSTEMS FOR
ULTRASENSITIVE SPECTROSCOPY AND BIODETECTION
Plasmonics,
by localizing light to the sub-wavelength volumes and dramatically enhancing
local fields, is enabling myriad of exciting opportunities for construction of
novel photonic devices and integrated nanophotonic systems. In this talk, I
will present our recent work on integrated on-chip plasmonics, nanofluidics,
and metamaterials and their applications in ultrasensitive spectroscopy and
biodetection.
10:20 DB2.7 FROM NEAR-FIELD TO FAR-FIELD: RADIATIVE
COUPLING OF PARTICLE PLASMON RESONANCES IN THREE-DIMENSIONAL GEOMETRIES
R. Taubert, H. Giessen, University of Stuttgart, Stuttgart, Germany
We
demonstrate superradiant-like eects in a three-dimensional arrangement of
particle plasmonic oscillators at Bragg distance. In a Bragg-stacked multilayer
structure we observe the formation of a very broad photonic band gap that spans
almost one octave in the optical frequency range.
10:40 End of the Session
Session Chairs: Terje Tjelta, R. Struzak
Session E05
Type Oral Presentation
Schedule Wednesday, August 17, 08:00-10:40
Room Galata
08:00 E05.1 PHYSICAL, TECHNICAL, PRACTICAL,
ECONOMICAL, AND REGULATORY ASPECTS OF SPECTRUM MANAGEMENT
The
radio spectrum is a highly value resource that call for efficient utilisation.
This includes robust interference tolerant radio equipment and cost-effective
spectrum management regimes. The pressure on suitable spectrum is high,
particularly for mobile data services. The management at all levels meets new
challenges: either it is traditional command and control methods or liberalised
market mechanisms. Spectrum for specified radio services and systems is
challenged by free utilisation of spectrum commons. The way forward is an
evolutionary path where laws of physics must be respected, but advance
technology allowed and more flexible regulatory regimes put into work.
08:20 E05.2 SPECTRUM CONSIDERATIONS FOR GLOBAL
BROADBAND ACCESS
C. Langtry, International Telecommunication Union, Geneva, Switzerland
ITU
plays a leading role in establishing the standards and spectrum arrangements
for the current IMT-2000 (3G) systems and for IMT-Advanced, which provides the
global platform for the next generations of mobile broadband services. It is
now timely to review the initial forecasts of spectrum requirements that were
made and to assess what further actions may be required to realize global
mobile broadbands vast potential to connect the world. This review is being
addressed in the ITU-Rs Study Group and Conference activities.
08:40 E05.3 FLEXIBLE SPECTRUM USAGE FOR THE FUTURE
BROADBAND MOBILE AND FIXED CONVERGENCE
L. Sun, Huawei, Beijing, China
To
meet the tremendous increase of user ever-increasing demands of on the global
market, it is necessary to find more available spectrum resources for the
future broadband mobile and fixed convergence. Under the current circumstance,
it is more important to strengthen sharing broadband applications with other
radio services. Instead of only calculating the deficiency of resources, we
need to try to find a solution through spectrum sharing with other services. we
provide two solutions of flexible spectrum usage for the mobile broadband
applications, from the operational and regulatory perspective.
09:00 E05.4 PERSPECTIVES AND PROBLEMS OF OPPORTUNISTIC
AND DYNAMIC SPECTRUM MANAGEMENT
M. R. Fitch, BT, Martlesham Heath, United Kingdom
Changes
in regulation are allowing secondary users to share spectrum with primary
users, for free subject to the condition that they do not interfere with the
primary users. Cognitive Radio (CR) is an enabling technology that allows such
sharing. It opens the way for opportunistic and dynamic spectrum management,
where wireless equipment is required to interface with cognitive algorithms,
sensing mechanisms and databases. The paper discusses the challenges and opportunities
that arise with such spectrum management.
09:20 Tea/Coffee Break
09:40 E05.5 OPPORTUNISTIC SECONDARY SPECTRUM ACCESS -
OPPORTUNITIES AND LIMITATIONS
J. Zander, K. W. Sung, Royal Institute of Technology (KTH), Stockholm, Sweden
Dynamic
spectrum sharing technique (Cognitive Radio) where secondary users
opportunistically utilize temporarily or locally unused spectrum has emerged as
a promising technology to relieve the perceived spectrum shortage. The QUASAR
project aims at a realistic assessment of the amount of spectrum available for
secondary use. Result show that it's fundamentally difficult to reliably
determine which part of the spectrum is available, which leads to large safety
margins consequently to poor spectrum utilization. Further, future business
success depends on the scalability of the secondary access techniques. Also,
the vast majorities of spectrum opportunities defy common models for spectrum
trading
10:00 E05.6 CONSERVATION OF SPECTRUM FOR SCIENTIFIC
SERVICES,- THE RADIO ASTRONOMICAL PERSPECTIVE
A. Jessner, Max Planck Institute for Radio Astronomy, Bonn, Germany
Scientific
services are indispensable for a technical society, but by their nature they
have more stringent protection requirements. These have also changed in the new
digital era. Scientific services are efficient in their use of allocated
bandwidth and utilise the highest possible detection sensitivity, but any
detectable man-made signal in their band jeopardizes their operation. There is
no free choice of frequencies, these are given by natural molecular transition
frequencies. As a consequence, only the scrupulous regulatory protection of
core frequencies for science can ensure the viability of scientific use of
radio spectrum for the benefit of all.
10:20 E05.7 MITIGATION OF EXTERNAL INTERFERENCE ON AN
EGSM NETWORK
T. U. Haq, wi-tribe, Islamabad, Pakistan; A. Iqbal, wi-tribe, Lahore, Pakistan
Wireless
Technologies are being used extensively for telecommunication services,
increasing possibility of inter-system interference. Interference management
becomes a challenge if same spectrum is allocated to different network
operators in neighboring countries. ITU and Regional Regulatory bodies provide
guidelines for coordinated spectrum allocations across international borders;
however, some scenarios are not addressed. One such problem is faced by an EGSM
operator in Pakistan which is facing interference from CDMA operators in India.
Coordinated frequency planning is not possible in this cross-technology
interference scenario. This paper describes analysis and mitigation of the
unique interference problem of the Pakistani EGSM operator.
10:40 End of the Session
F05 – Radar Applications: Polarimetric Interferometry, Smart Systems and Propagation Impairment
Session Chairs: Alberto Moreira, Eric Pottier
Session F05
Type Oral Presentation
Schedule Wednesday, August 17, 08:00-10:40
Room Haliç
08:00 F05.1 SUBSURFACE TOPOGRAPHY MAPPING IN DESERTS
USING TWO FREQUENCY SAR INTERFEROMETRY
K. Sarabandi, A. Elsherbini, The University of Michigan, Ann Arbor, United States
The
progress in the development of a new two frequency InSAR system for mapping the
subsurface topography in deserts and arid regions is presented. The proposed
system consists of a Ka-InSAR for mapping the top interface topography and a
VHF-InSAR for mapping the subsurface topography. The required modifications in
conventional InSAR inversion to allow for height estimation in the presence of
the top layer are then presented. Some of the image distortions that occur in
the SAR images are also presented. Scaled model measurements were performed to
verify the operation of the proposed system.
08:20 F05.2 MILLIMETER-WAVE GROUND BASED SYNTHETIC
APERTURE RADAR MEASUREMENTS
In
this study, applications of millimeter wave ground based synthetic aperture
radar (GB-SAR) experiments are studied. GB-SAR setup is constructed and
measurements of different objects are carried out in the semi-anechoic chamber
room. Measurements from targets at the millimeter wave regions are collected by
the newly constructed measurement setup. Also, real SAR measurement from metal
targets is taken. Then, the millimeter wave GB-SAR images are reconstructed by
using a matched filtering type algorithm and the performance of the setup is
quantified from the resultant images by evaluating the accuracy and quality
metrics.
08:40 F05.3 ESTIMATING AMBIGUITY NUMBER OF RADIAL
VELOCITY FOR GROUND MOVING TARGETS FROM A SINGLE SAR SENSOR
S. Zhu, G. Liao, Xidian University, xi'an, China
This
paper addresses an ambiguity number estimation approach of cross-track velocity
for ground moving targets from a single synthetic aperture radar (SAR) sensor.
We first transform the target signatures into range frequency domain and then
compress it for each range frequency. The resulting compressed envelope
exhibits a straight line with its slope just proportional to the ambiguity
number of the induced Doppler centroid. The true radial velocity can be
completely retrieved. For dim moving targets, an improved estimation strategy
is introduced. The effectiveness of this approach is demonstrated by the
theoretical analysis and real measured SAR data
09:00 F05.4 DESIGN AND IMPLEMENTATION OF AN AUTOMATIC
CRUISE CONTROL RADAR FOR SMART VEHICLE
S. Bera, D. Bhaskar, R. Bera, Sikkim Manipal Institute of Technology, Rangpo, Sikkim, India
Smart
vehicles are evolving for collision avoidance after the success stories of
airborne SAR for air traffic detection and control. Efforts for the development
of such vehicular radar using spread spectrum waveform are attempted by
authors. Model based design and simulation of the radar system along with
target modeling and ISAR imaging are successfully completed. Baseband and IF
portion of the radar model are realized by uploaded and downloaded to Arbitrary
waveform generator and Vector signal generator respectively. The total radar
system with ISAR Imaging are successfully tested at the open range of the
authors premises with multiple standard targets.
09:20 Tea/Coffee Break
09:40 F05.5 GENERALIZED ISAR IMAGING OF SEA TARGET
A. D. Lazarov, Burgas Free University, Burgas, Bulgaria
A
GISAR approach to solve SAR problem for ship target imaging is considered.
Definition of three dimensional SAR scenario is suggested. Analytical
geometrical approach to define apparent Yaw, Pitch and Roll angle of a ship
target at sea is implemented. The target is presented as an assembly of point
scatterers. Mathematical expressions to calculate distance to each point
scatterer are derived. SAR signal model based on a linear frequency modulated
signal and reflectivity function of the target is derived. Image reconstruction
includes Fourier range and azimuth compressions. To verify GISAR models and
image reconstruction concept a numerical experiment is performed.
10:00 F05.6 INFERENCE OF SPATIAL CORRELATION
CHARACTERISTICS OF RAINFALL INTENSITY FROM THE DATA OF SATELLITE-BORNE
PRECIPITATION RADAR AND GROUND-BASED RAIN GAUGES
T. Manabe, R. Jozaki, Osaka Prefecture University, Sakai, Osaka, Japan
Spatial
correlation characteristics of rainfall are crucial in predicting rain attenuation
statistics for wireless links above 10 GHz. In this paper, we propose a method
for estimating the spatial correlation characteristics of rainfall from the
data measured by a satellite-borne radar and a ground-based raingauge. By
applying this method to the data measured by the Precipitation Radar aboard the
TRMM satellite and those of ground-based raingauges provided by Japan
Meteorological Agency, estimated spatial correlation characteristics are found
to be consistent with those reported in literatures around Tokyo and to show
regional dependence in central and western Japan.
10:20 F05.7 SOUNDING SIGNALS LIBRARY FOR
RECONFIGURABLE POLARIMETRIC FM-CW RADAR PARSAX
G. Babur, O. Krasnov, A. Yarovoy, TU Delft, Delft, Netherlands
Diversity
of sounding signal waveforms for polarimetric FM-CW radar is studied. Each
signal represents a pair of mutually orthogonal wavelets which can be
transmitted via two orthogonal polarizations. The signals compose a waveform
library which has been implemented in the operational polarimetric
software-defined radar PARSAX. This paper presents a sounding signals library
for polarimetric FM-CW radar. All the considered in this paper waveforms have
been implemented in the operating polarimetric radar (in its FM-CW mode),
namely in the PARSAX radar system developed in Delft, The Netherlands.
10:40 End of the Session
G05 – New Science Initiatives on Irregularities and Scintillation using Beacon Satellites
Session Chairs: Patricia Doherty, Paul Bernhardt
Session G05
Type Oral Presentation
Schedule Wednesday, August 17, 08:00-10:40
Room Topkapi A
08:00 G05.1 THE TANDEM INSTRUMENTED CUBESATS
EXPERIMENT (TICE) IN LOW EARTH ORBIT FOR CONTINUOUS OCCULTATION OBSERVATIONS OF
THE IONOSPHERE
A
new concept, called the Tandem Instrumented CubeSats Experiment (TICE), has
been developed using a pair of cubeSats orbiting in tandem in an a common orbit
plane. With a ~4000 km range between the satellites, the propagation path will
have constant tangent height around 80 km altitude well below the E- and
F-layer ionospheres. The radio link between the transmitter CubeSat and
receiver cubesat will be continuous so that there will be no data gaps in the
ionospheric measurements. Ionospheric irregularities will be triangulated from
the tandem satellite observations to provide both location and scintillation
strength.
08:20 G05.2 EQUATORIAL SCINTILLATION PREDICTIONS FROM
C/NOFS PLANAR LANGMUIR PROBE ELECTRON DENSITY FLUCTUATION DATA
Data
from the Planar Langmuir Probe onboard Communication/ Navigation Outage
Forecasting System will be combined with coherent scatter radar and
scintillation measurements to analyze the performance of different propagation
models of satellite signals. This work characterizes: (i) the prediction
capability of a purely space-based phase-screen scintillation model in
comparison with another that represents the variation of the irregularity
strength along ray paths in detail; and (ii) how early in time it is possible
to detect irregularity structures, estimate their temporal and spatial
evolution and predict their effects on propagation through different
ionospheric regions at later instants of time.
08:40 G05.3 C/NOFS IN SITU AND BEACON MEASUREMENTS
DURING THE MAIN PHASE OF THE FIRST MAGNETIC STORMS WITHIN SOLAR CYCLE 24
The
study utilizes the high resolution PLP and the beacon on the C/NOFS satellite
to determine the impact on the equatorial ionosphere of two moderate magnetic
storms during solar cycle 24. These two storms perturb various SCINDA sites at
dusk. The in-situ C/NOFS data allows the tracking of the plasma bubbles on a
global scale. The spectral analysis of the PLP data shows interesting variation
in the spectral shapes depending on its location with respect to the bubbles.
Current analysis is ongoing to determine the impact of the spectral shapes on
UHF scintillations from C/NOFS.
09:00 G05.4 GNU RADIO BEACON RECEIVER (GRBR)
OBSERVATIONS OF LARGE-SCALE WAVE STRUCTURE (LSWS) AND EQUATORIAL SPREAD F (ESF)
GNU
Radio Beacon Receiver (GRBR) is a new digital receiver based on GNU Radio and
USRP (Universal Software Radio Peripheral) [Yamamoto, 2008]. In this paper, the
GRBR observations of large-scale wave structure (LSWS) and the subsequent
development of equatorial spread F (ESF) using total electron content (TEC)
derived from the ground based reception of signals from the radio beacon on
board C/NOFS (Communications/Navigation Outage Forecasting System) satellite
are presented. The other evidences of LSWS include the satellite traces observed
in ionograms. These observations show that LSWS appears to play an important
role in the development of ESF.
09:20 Tea/Coffee Break
09:40 G05.5 GLOBAL S4 INDEX OBSERVED BY
FORMOSAT-3/COSMIC DURING 2006-2011
The
global FORMOSAT-3/COSMIC S4 index are subdivided and examined in various
latitudes, longitudes, altitudes, and seasons. The F-region scintillations in
the equatorial and low-latitude ionosphere start around post-sunset period and
often persist till post-midnight hours during the March and September equinox
as well as December Solstice seasons. The E-region scintillations reveal a
clear solar zenith effect and yield pronounced intensities in mid-latitudes
during the Summer Solstice seasons, which are well correlated with occurrences
of the sporadic E-layer. There is no obvious scintillation activity observed in
the high-latitude ionosphere.
10:00 G05.6 SCINTILLATIONS ON LEO POLAR ORBITING
BEACON SIGNALS IN PRESENCE OF SPORADIC E LAYERS RECORDED BY EISCAT
Ionospheric
plasma density irregularities may cause rapid fluctuations in the intensity and
phase of radio waves propagating through. Usually, scintillation events are
modelled in the diffractive scattering approach which is valid for weak scattering
conditions. Strong scintillation events are better modelled in the refractive
scattering approach, which includes weak scattering conditions. Two EISCAT
measurement campaigns were set up in order to calculate all those parameters
useful for numerical modelling of scintillation events. The radar measurement
results are compared with transionospheric radio signals at VHF, UHF, and L
band in order to understand the feasibility and appropriateness of the two
approaches.
10:20 G05.7 INVESTIGATION OF TEC VARIATION AND
IONOSPHERIC SCINTILLATION AT THE TWO HEMISPHERES OVER THE POLAR REGION USING
GPS MEASUREMENTS
The
main of the presented work is to investigate the generation of polar plasma
patches and ionospheric scintillations over Maitri, Antarctica [70.43N, 11.43E]
and Himadri, Arctic [78.55N, 11.56E]. To explore the difference between the
behaviour of day and nighttime polar region ionosphere, the data during
June-July 2008 have been used. The results show that the ionospheric irregularities
were observed at both the stations and it is seen that the scintillation are
associated with these patches. The irregularities caused strong Total Electron
Content fluctuations which are horizontally drifted from east to west
10:40 End of the Session
HG1 – Radio Sounding in Ionospheres and Magnetospheres and Associated Plasma Phenomena I
Session Chairs: Robert Benson, Bodo Reinisch, Gordon James, Vikas Sonwalkar
Session HG1
Type Oral Presentation
Schedule Wednesday, August 17, 08:00-10:40
Room Topkapi B
08:00 HG1.1 RADIO SOUNDING FROM IMAGE: NEW
PERSPECTIVES ON FIELD ALIGNED DENSITY IRREGULARITIES, Z AND WHISTLER MODE
DIAGNOSTICS, AND PROTON CYCLOTRON HARMONIC ECHOES, PART 1
The
wide operating frequency range of the Radio Plasma Imager (RPI) instrument on
the IMAGE satellite made possible wave injection in the whistler-mode and
Z-mode domains as well as free-space O and X mode sounding. We review new
findings in four areas: (i) density irregularities in the PBL and within the
plasmasphere; (ii) upward Z-mode probing along geomagnetic field lines; (iii)
downward probing from 4500-7000 km altitude using whistler-mode waves that
undergo two fundamentally different types of reflection; (iv) strong coupling
of RPI pulses to the proton plasma in the vicinity of the spacecraft.
08:20 HG1.2 RADIO SOUNDING FROM IMAGE: NEW
PERSPECTIVES ON FIELD ALIGNED DENSITY IRREGULARITIES, Z AND WHISTLER MODE
DIAGNOSTICS, AND PROTON CYCLOTRON HARMONIC ECHOES, PART 2
The
wide operating frequency range of the Radio Plasma Imager (RPI) instrument on
the IMAGE satellite made possible wave injection in the whistler-mode and
Z-mode domains as well as free-space O and X mode sounding. We review new
findings in four areas: (i) density irregularities in the PBL and within the
plasmasphere; (ii) upward Z-mode probing along geomagnetic field lines; (iii) downward
probing from 4500-7000 km altitude using whistler-mode waves that undergo two
fundamentally different types of reflection; (iv) strong coupling of RPI pulses
to the proton plasma in the vicinity of the spacecraft.
08:40 HG1.3 WHISTLER MODE RADIO SOUNDING FROM THE RPI
INSTRUMENT ON THE IMAGE SATELLITE
Whistler
mode (WM) sounding experiments from the RPI instrument on IMAGE have led to the
observations of magnetospherically reflected (MR), specularly reflected (SR),
and back scattered (BS) echoes. The observed dispersion of MR and SR echoes is
used to infer the electron density, ion effective mass, and the ion composition
along the geomagnetic field line, including the important transition region
from the O+ dominated ionosphere to the H+ regime above. The observed spread in
time delays of echoes is used to determine the scale sizes (10 m -100 km) and
locations of field aligned irregularities along WM echo paths.
09:00 HG1.4 SPECTRAL INTERPRETATION OF
RADIO-SOUNDER-STIMULATED MAGNETOSPHERIC PLASMA RESONANCES IN TERMS OF KAPPA
DISTRIBUTIONS
Magnetosphere
sounders stimulate plasma resonances between the harmonics of the electron
cyclotron frequency and above the upper-hybrid frequency. More than three
decades ago they were recognized as equivalent to ionospheric
topside-sounder-stimulated resonances, designated as Qn resonances a decade
earlier, with one important difference: the magnetospheric Qn frequencies often
indicated that the background electron-velocity distribution was
non-Maxwellian. Interpretations based on bi-Maxwellian and kappa distributions
have been proposed. Here we expand on the latter, which requires fewer free
parameters, by comparing kappa-derived Qn frequencies with observations from
the Radio Plasma Imager on the IMAGE satellite.
09:20 Tea/Coffee Break
09:40 HG1.5 DAYTIME VLF MODELING OVER LAND AND SEA,
COMPARISON WITH DATA FROM DEMETER SATELLITE
A
model based on Wait's mode theory and ionospheric parameters is developed to
investigate subionospheric VLF wave propagation. Although the bulk of VLF
energy reflects off the lower ionosphere, a small portion leaks into space.
This leaves a fingerprint of the modal interference pattern. This pattern can
be detected by spacecraft and is a good method of observing the field's spatial
variation and the effects of different propagation conditions. Simulations are
compared to averaged data taken over a year from the DEMETER satellite over the
NWC transmitter.
10:00 HG1.6 REFRACTIVE INDEX OF SPHERICAL WAVES IN
MAGNETOPLASMA
The
electromagnetic field excited by an arbitrary current source embedded in a
uniform cold magneto-plasma is investigated in this paper. The Greens function
method for solving the radiation equation is used, and the solutions we
obtained are valid for any cold plasma parameters. There are always two wave
modes excited, and in the far field each mode is a spherical wave. A refractive
index of spherical waves is introduced to describe the propagation. The
properties of these excited spherical waves are discussed in this paper.
10:20 HG1.7 A NEW TYPE MULTI-FUNCTION IONOSPHERIC
SOUNDING SYSTEM
G. Yang, Z. Zhao, C. Zhou, Y. Zhang, G. Chen, Y. Hu, Wuhan University, Wuhan, China
This
paper introduces a new type Multi-Function Ionospheric Sounding System (MFISS),
which bases on the PXI bus. The capabilities of ionospheric vertical sounding,
ionospheric oblique sounding and ionospheric oblique backscattering sounding
were integrated in a single MFISS, it overcomes the disadvantages of the
original ionospheric sounding equipments which have the feature with less
function, limited coverage, less obtaining parameters, it also can achieve the
function of acquiring the omnibearing geophysical characteristics, the ionosphere
channel propagation characteristics and the radio environment characteristics.
10:40 End of the Session
J05 – Sun and Solar System Science
Session Chairs: Pierre Kaufman, Noah Brosch
Session J05
Type Oral Presentation
Schedule Wednesday, August 17, 08:00-10:20
Room Marmara
08:00 J05.1 MUSAR A NOVEL SAR MISSION TO VENUS
The
science community is currently considering new missions to explore Venus,
focusing on key measurements that will answer the major outstanding questions
for Venus that will remain after the current Venus Express mission. A new
lightweight X-band SAR mission is being proposed as a Discovery class mission
to Venus. This mission will utilize an X-band synthetic aperture radar capable
of acquiring imagery at high (~1 m) resolutions for specifically targeted
sites. The sensor is based on the Israel Aerospace Industry (IAI) TecSAR sensor
that is already orbiting Earth and acquiring spectacular images.
08:20 J05.2 THE UNUSUAL SOLAR CYCLE 23: THE VANISHING
SOLAR WIND, ITS CAUSE AND IMPACT
Solar
cycle 23 was very unusual, in many ways, with polar magnetic fields showing a
steady decline throughout the cycle and with the sunspot minimum being the
deepest that we have experienced in a century. Apart from this cycle 23 had
several instances when the solar wind apparently ``disappeared" for
periods exceeding 24 hours. We examine these solar wind disappearance events
which correspond to density decreases, at 1 AU, by over two orders of magnitude
for extended periods of time and show that these events, though not associated
with explosive solar phenomena, produce observable space weather effects at 1
AU.
08:40 J05.3 SOLAR PHYSICS AT NANCAY RADIO OBSERVATORY
(FRANCE) : RECENT DEVELOPMENTS
K.-L. Klein, Observatoire de Paris, Meudon, France
The
Nancay station of Paris Observatory operates two key instruments for solar
physics: the Decametre Array (dynamic spectra, 20-70 MHz) and the
Radioheliograph (images in the 150-450 MHz range). A new spectrograph (130-1000
MHz) is under construction for scientific and space weather purposes. This
contribution summarises performances of the instruments and illustrates recent
results on the quiet Sun, quasi-continuous particle acceleration in active
regions (noise storms) and coronal mass ejections and solar energetic particle
events. Such observations will be an essential support in future investigations
of the Sun-Heliosphere connection with Solar Orbiter and Solar Probe.
09:00 J05.4 THE RADIOSICENCE EXPERIMENT ON NEW
HORIZONS
REX
is the Radioscience Experiment in the payload on the New Horizons spacecraft
en-route to its encounter with Pluto in July of 2015. REX will obtain the
temperature and pressure profiles of Pluto's tenuous atmosphere while measuring
radiometric temperature, gravitational moment and ionosphere density. For all
but the radiometry, these measurements take advantage of a high power, X-band
uplink transmitted from the earth, received on the spacecraft with an
ultrastable oscillator as a frequency reference. This combination enables REX
to sense Pluto's atmosphere with precision of <0.1 Pa (1 microbar), and
<3 K.
09:20 Tea/Coffee Break
09:40 J05.5 SOLAR SYSTEM STUDIES WITH THE ARECIBO
PLANETARY RADAR SYSTEM
The
305 m Arecibo telescope equipped with a 1 MW 2.38 GHz transmitter is used for
studies of the terrestrial planets, planetary satellites including the Moon and
small bodies in the solar system. Much of the recent program emphasis has been
on astrometric and characterization observations of near-Earth objects for
which the Arecibo radar system has capabilities not matched by any other
Earth-based telescope. However, studies of the surfaces of Mercury, the Moon
and Mars continue and renewed observations of Venus are planned.
10:00 J05.6 PROGRESS ON CHINESE SPECTRAL
RADIOHELIOGRAPH－CSRH CONSTRUCTION
The
Chinese Spectral Radioheliograph (CSRH) with 40 antennas of 4.5 m covering 400
MHz 2 GHz (CSRH-I) and 60 antennas of 2 m covering 2-15 GHz (CSRH-II) has been
supported and is under construction in a radio quiet region in Inner Mongolia
of China. The array of CSRH-I has been assembled and is tested now. The array
of CSRH-II will be established during 2011-2013. The progress about the project
is introduced.
10:20 End of the Session
K04 – Biomedical Applications: Diagnostic Sensing
Session Chairs: James Lin, Jan Vrba
Session K04
Type Oral Presentation
Schedule Wednesday, August 17, 08:00-10:40
Room Loft
08:00 K04.1 WIRELESS SENSING AND MONITORING OF
PHYSIOLOGICAL MOVEMENTS AND VOLUME CHANGES
J. C. Lin, University of Illinois at Chicago, Chicago, IL 60607, United States
There
has been growing interest in the use of low-power wireless technology for
contact and remote detection and monitoring of physiological movements and
volume changes. Remote or non-contact sensing of body movements associated with
the expansion and contraction of the circulatory and respiratory systems.
Wireless techniques provide an approach for detecting physiological and
pathological movements and volume changes without compromising the integrity of
the physiological substrates. Non-invasive measurements can provide sensing and
monitoring for apex cardiograms, respiration rate, peripheral blood pulse wave,
pressure pulse characteristics, arterial wall movement, and life sign (heart
rate and respiration rate) detection.
08:20 K04.2 DESIGN AND REALIZATION OF ULTRA WIDE-BAND
IMPLANT ANTENNA FOR BIOTELEMETRY SYSTEMS
The
aim of this study is to design of a small size implantable antenna involving
Industrial, Scientific and Medical (ISM) (2.4 GHz-2.48 GHz) band. The goal of
designing antenna is to obtain physiological information pertaining to person.
Simulation measurements of antenna were obtained in body ambient by making the
design of antenna with CST Studio Suite programme. Then, in vitro measurements
were performed on antenna by making an artificial material, which shows
electrical features of human skin tissue, to verify measurement results.
Obtained measurement results and simulative results are in accordance.
08:40 K04.3 MICROWAVE IMAGING FOR MEDICAL DETECTIONS
G. G. Cheng, Y. Zhu, J. A. Grzesik, Allwave Corporation, Torrance, CA, United States
We
introduce an efficient microwave imaging technique for medical applications,
especially suited for breast cancer detection. The imaging system consists of a
fixed source for transmit on one end, and a planar receiving sensors on the
other, with the target placed in between. The image of the internal organ
tissue under examination is thus obtained across a three-dimensional region,
based upon the data collected from these sensors, using our field mapping
algorithm (FMA). Six test cases, including analytic examples, FDTD simulation
runs, and hardware measurements, are given for verification, with promising
results evident throughout.
09:00 K04.4 COMPACT RESONATORS FOR PERMITTIVITY
RECONSTRUCTION OF BIOLOGICAL TISSUES
T. Yilmaz, Y. Hao, Queen Mary College, University of London, London, United Kingdom
In
this paper, a patch resonator is proposed for non-invasive measurement of
dielectric properties of biological tissues. Resonator is operating at 2.4 GHz
when placed on tissue. The patch resonator is simulated in HFSS with four
layered tissue mimicking material (skin, fat, blood, muscle) placed on top. The
electrical properties of blood layer is decreased and the change in S
parameters is tracked. Effective dielectric properties of the tissue is
reconstructed from simulated S parameter response of the resonator.
09:20 Tea/Coffee Break
09:40 K04.5 BIORADAR FOR MONITORING OF HUMAN ADAPTIVE
CAPABILITIES
This
paper sums up the results of bioradiolocation experiments dedicated to the
monitoring of human adaptive capabilities, which were conducted at Remote
Sensing Laboratory (Bauman Moscow State Technical University) during last two
years. The main task of bioradiolocation is remote or non-contact measurement
of movement, breathing and pulse parameters of biological objects behind an
obstruction or in open space at some distance. This method can be used in sleep
medicine, functional diagnostics, pharmacology, zoo-psychology, restorative
medicine and disaster medicine. Description of the bioradar experimental
procedure is given.
10:00 K04.6 THROUGHPUT OF OPTIMAL AND SUBOPTIMAL
LOW-POWER IR-UWB COHERENT RECEIVERS FOR WIRELESS BODY-AREA-NETWORKS (WBANS)
Impulse
radio ultra wide band (IR-UWB) systems have the potential for low-power
consumption as well as high data-rates over short distances. This makes them an
attractive candidate for emerging wireless body-area-network (BAN)
applications. In this paper, we investigate the performance of low-power
suboptimal real sinusoidal-template based detectors for M-ary
pulse-amplitude-modulation (PAM) and M-ary equally-correlated
pulse-position-modulation M-ary (EC-PPM) modulation techniques in multipath
channels. Furthermore, we provide numerical results in the UWB-based IEEE
802.15.6a channels, and evaluate the corresponding attainable throughput.
10:20 K04.7 GLUCOSE-DEPENDENT DIELECTRIC PROPERTIES OF
BLOOD PLASMA
In
this study, we show a correlation between electrical properties (relative
permittivity and conductivity) of blood plasma and plasma glucose
concentration. In order to formulate that correlation, we performed electrical
property measurements on blood samples collected from 10 adults between the
ages of 18 and 40 at University of Alabama Birmingham (UAB) Children's
hospital. The measurements are conducted between 500 MHz and 20 GHz band. Using
the data obtained from measurements, we developed a single-pole Cole-Cole model
for permittivity and conductivity as a function of plasma blood glucose
concentration.
10:40 End of the Session
CT – Six-port Wave Correlator Theory and Practical Application to RF Network Analysis
Session Chair: Takashi Ohira
Session CT
Type Oral Presentation
Schedule Wednesday, August 17, 09:40-10:40
Room Dolmabahçe A
09:40 CT.1 SIX-PORT WAVE CORRELATOR THEORY AND
PRACTICAL APPLICATION TO RF NETWORK ANALYSIS
T. Yakabe, The University of Electro-Communications, Tokyo, Japan
This
tutorial lecture is intended to introduce the basic concept and principle of
the six-port wave correlator, and to present the latest advancements in its
theory and techniques. The lecture starts with some fundamentals on the
six-port reflectometer. Next, the concept is extended to a six-port wave
correlator on which we focus from the viewpoint of establishing a new scheme
for characterizing the S matrix. Finally, we explore some specific microwave
applications of the six-port network. The lecture is full of interesting ideas
and techniques for a variety of applications in microwave and millimeter-wave
fields.
10:40 End of the Session
Session Chair: Michael Rietveld
Session GL2
Type Oral Presentation
Schedule Wednesday, August 17, 11:00-12:00
Room Anadolu Auditorium
11:00 GL2.1 THE RADIO PHYSICS OF METEORS: HIGH RESOLUTION RADAR METHODS OFFERING NEW INSIGHTS
A. Pellinen-Wannberg, Umeå University and Swedish Institute of Space Physics, Kiruna, Sweden
The
introduction of the high-power large-aperture (HPLA) radar method has
rejuvenated meteor radiophysics. Operating at much shorter wavelengths and with
orders of magnitude higher power densities than meteor radars, HPLA radars
record head echoes throughout the meteor region. Parameters like meteoroid
orbital elements, astronomical origin, meteor velocity, deceleration,
composition, fragmentation, breakup, echo polarization and plasma physics can
be studied with unprecedented accuracy, often in microsecond time resolution,
adding important new elements to our knowledge of the solar system dust
population. The development from 1990 to the present will be reviewed and some
recent breakthroughs highlighted.
12:00 End of the Session
Session Chair: William Davis
Session AB2
Type Oral Presentation
Schedule Wednesday, August 17, 13:40-17:20
Room Dolmabahçe C
13:40 AB2.1 DESIGN OF WIDEBAND DUAL-POLARIZED
MICROSTRIP ANTENNAS
J. S. Jeon, KT Mobile R&D Laboratory, Seoul, South Korea
This
study investigates wideband dual-polarized microstrip antennas. These antennas
are used to prevent deterioration of transmission quality caused by terminal
interference or multipath fading, which usually occur when many terminals are
used in limited space such as hot-spot zones. The experimental results showed
that the impedance bandwidth (SWR<2) of 33.24 % and the peak gain of 8.44
dBi (at 2.11 GHz) were obtained by the frequency band under 2.5 GHz. Designed
originally for triple service band, the proposed antenna, with its simple
structure, may easily be mass-produced and may have various commercial
applications.
14:00 AB2.2 DUAL FREQUENCY RECONFIGURABLE MICROSTRIP
ANTENNA USING VARACTOR DIODES
N. M S, A. C K, M. Pezholil, V. Kesavath, Cochin University of Science and Technology, Cochin, India
A
varactor controlled electronically reconfigurable dual frequency microstrip
antenna is presented. Dual frequency operation is realized by embedding an
X-slot in a rectangular patch. High tuning ranges of 26.3% and 15.3% are
realized for the two resonant frequencies respectively, when the bias voltage
is varied from 0 to 16V. This design has an added advantage of size reduction
up to 77% and 64% for the two resonant frequencies compared to standard
rectangular patch. A maximum band width of 2.26% and 2.36% respectively for the
two frequencies is observed.
14:20 AB2.3 A BROADBAND DESIGN OF H-SHAPED MICROSTRIP
ANTENNA WITH CAPACITIVE FEEDING
A
H-shaped Microstrip patch antenna with capacitive feed is presented here,
overcome various problems in other feeding, capacitive feeding scheme has used
which consist of radiator patch and feed strip. The design of antenna
incorporates capacitive feed strip which is fed by coaxial probe. Slot is used
in the radiating patch along radiating edges of the proposed design to attain
the improved bandwidth. Constant radiation pattern with improved VSWR bandwidth
of nearly 46%, for operating frequency of 5.1GHz is easily achieved. The
effects of key design parameters like air gap between substrate and ground
plane etc. are studied.
14:40 AB2.4 U-SLOT STACKED PATCH ANTENNA USING HIGH
AND LOW DIELECTRIC CONSTANT MATERIAL COMBINATIONS IN S-BAND
K. Surmeli, TUBÝTAK-BÝLGEM, Kocaeli, Turkey
In
this study a uslot stacked patch antenna design is presented. The antenna
consist of high and low dielectric materials combination in S band. Materials
are commercially available microwave substrates (Rogers TMM3 and Rohacell HF71
foam). The antenna return loss bandwidth is about 52.94%, centered about 3.4
GHz and the fabrication of the antenna is more easier.
15:00 AB2.5 CIRCULARLY POLARIZED MICROSTRIP PATCH
ARRAY FOR WIRELESS COMMUNICATION APPLICATIONS
In
recent years, great interest was focused on Microstrip antennas for good
integration and good performance. With the continuous growth of wireless
communication service and the constant miniaturization of communication
equipment, there are higher demands for the volume of antennas, integration and
working band. This paper presents A circular polarized (CP ) Circular
Microstrip antenna array with multi- band for wireless communications system
application which are suitable for 2.92GHz, 4.3GHz, 5GHz triple-band operations.
These systems include various combinations of WiMAX (Worldwide Interoperability
for Microwave Access) and wireless local-area network (WLAN, 2.8 GHz for
wireless video operation).
15:20 AB2.6 CAPACITIVE FEEDING FOR SLOTTED MICROSTRIP
PATCH
A
Microstrip patch antenna having slotted sides with small capacitive feed has
studied. Slots on the proposed patch can be used to increase the bandwidth of
antenna. It has observed that VSWR bandwidth nearly 45% is easily achieved with
the novel patch. A constant radiation pattern with improved bandwidth, for an
operating frequency of 4.8 GHz is achieved. The given patch is radiating patch
while feed strip couples the energy to radiating patch by capacitive mean.
Effect of various parameters such as air gap between substrate and ground
plane, probe diameter etc on performance of the antenna has studied .
15:40 Tea/Coffee Break
16:00 AB2.7 LINEARLY POLARISED MICROSTRIP ANTENNA FOR
WLAN APPLICATIONS
A
novel compact linearly polarized square microstrip antenna with four slits and
rectangle notches at four corners is proposed . The center frequency of the
microstrip antenna operates at 6GHz and it has about 4% bandwidth with
VSWR<2. The design and performance of a linearly polarized microstrip patch
antenna, for the application in Wireless Local Area Network, are reported here.
The aim is to design and fabricate an inset fed rectangular Microstrip Antenna
and study the effect of antenna dimensions length,, width and relative
dielectric constant, substrate thickness on radiation parameters of band width.
16:20 AB2.8 SIMULATION OF A RECTANGULAR SPIRAL SHAPED
MICROSTRIP PATCH ANTENNA
A. Aoad, E. Korkmaz, Fatih University, Istanbul, Turkey
For
some applications it is required to design antennas operating at lower
frequencies, have relatively low lateral size and a narrow beam broadside
radiation pattern. To that end a new rectangular spiral shaped microstrip
antenna is designed and simulated by using of commercial software CST Microwave
Studio. The parameters are optimized to have an operation frequency around
1-3.5 GHz, maximum lateral size of 3.5 cm, a minimum directivity of 6 dBi and a
HPBW less than 90. The achieved results are promising and are tunable to
specific parameters.
16:40 AB2.9 A NEW EFFECTIVE ANTENNA FOR MOBILE
HEADSETS
M. Bank, M. Haridim, HIT, Holon, Israel; S. Tapuchi, J. Gavan, SCE, Beer Sheba, Israel
The
main problems concerned with the design of mobile headsets antennas treated in
this paper are low efficiency and the difficulty of installing two antennas or
more for Multiple Input-Multiple Output (MIMO) applications. This paper
proposes a radical solution to the mentioned problems by avoiding the use of
special antennas as radiating elements. The proposed efficient radiating
element is the mobile headset printed circuit board. The proposed solution is
compared with other classical solutions.
17:00 AB2.10 COMPACT COPLANAR WAVEGUIDE FED GROUND
MEANDERED ANTENNA FOR WIRELESS APPLICATION
A
compact Co-Planar Waveguide (CPW) fed antenna operating at 2.4GHz with 300MHz
2:1 VSWR bandwidth is presented. Compared to a conventional quarter wavelength
CPW fed monopole antenna, the aperture area reduction of the present antenna is
85%. The prototype antenna fabricated on a substrate of εr = 4.4 and
thickness 1.6mm is only 22x10x1.6mm3. This much size reduction and impedance
matching is achieved by adjusting the signal to ground plane separation and
meandering the ground plane of a 50Ω CPW transmission line
17:20 End of the Session
Session Chairs: Tapan Sarkar, Magdalena Salazar-Palma
Session B07
Type Oral Presentation
Schedule Wednesday, August 17, 13:40-17:20
Room Anadolu Auditorium
13:40 B07.1 THEORETICAL ANALYSIS OF A VARACTOR-LOADED
HALF-WIDTH LEAKY-WAVE ANTENNA
Maintaining
a narrow beamwidth is difficult for a linear phased array antenna comprised of
wide beamwidth antenna elements with peak gain direction normal to the axis of
the array as the beam is steered close to end-fire. Rather, use of near
end-fire antennas, either singly or arrayed, offer the potential for achieving
reasonably narrow beamwidth even as the beam is steered near endfire. For
applications requiring wide bandwidth as well, half-width leaky-wave antennas
offer a potential element. Unfortunately, the beam direction is dispersive. In
this paper, a method is presented using varactors to overcome these challenges.
14:00 B07.2 DESIGN AND OPTIMIZATION OF ANTENNA ARRAYS
FOR 60 GHZ HYBRID SMART ANTENNA SYSTEMS WITH CONSIDERATION OF INTER-ELEMENT
ELECTROMAGNETIC INTERACTIONS
Use
of directive elements, element tilting, and using subarrays are proposed to
reduce computational complexity and cost of smart antennas. This approach,
namely the Hybrid Smart Antenna System combines advantages from both the
adaptive and switched beam approaches. A genetic algorithm based array
optimization procedure that determines the element tilt angles to uniformly
cover a given angular range by adaptive beamsteering has also been proposed for
60 GHz wireless applications. In this paper, additional considerations, namely
the electromagnetic interactions between the array elements are considered and
a more realistic implementation and optimization of the hybrid smart antenna
technique is discussed.
14:20 B07.3 GEODA-GRUA: ADAPTIVE MULTIBEAM CONFORMAL
ANTENNA FOR SATELLITES COMMUNICATIONS
GEODA-GRUA
is a conformal adaptive antenna array for satellite communications. Operating
at 1.7 GHz with circular polarization, it is possible to track and communicate
with several satellites at once being able to receive signals in full azimuth
and within the range of 5 to broadside elevation thanks to its adaptive beam.
Its complex structure has 2700 radiating elements based on a set of 60 similar
triangular arrays that are divided in 15 subarrays of 3 radiating elements. A
control module governs each transmission/receiver module associated to each
cell in order to manage beam steering by shifting phases.
14:40 B07.4 USE OF A SINGLE SNAPSHOT BASED ADAPTIVE
PROCESSING USING A DIRECT DATA DOAMIN APPROACH
T. Sarkar, Syracuse University, Syracuse, United States; M. Salazar, Univ Carlos III, Madrid, Spain
The
objective of this presentation is to describe a general methodology for
adaptive processing using conformal arrays for a single snap shot of data and
without any statistical assumption on the noise and the interferences. The
antenna elements in a conformal array can be unequally spaced and they need not
be situated over a planar surface. In addition the antenna elements can have a
directive gain. The goal is to present a signal processing methodology coupled
with electromagnetic physics that can deal with non-uniformly spaced directive
antenna elements over a conformal surface.
15:00 B07.5 ANALYSIS OF THE ELECTROMAGNETIC DEGREES OF
FREEDOM IN MULTI-ANTENNAS COMMUNICATIONS SYSTEMS
M.-F. Wong, A. Gati, J. Wiart, Orange labs, R&D, Issy Moulineaux, France
The
channel capacity enhancement is of great interest in broadband wireless
communications. The spatial dimension is being investigated with the use of
multi-antennas systems. The role of the antennas, their numbers and their
positions are to be understood through an electromagnetic analysis. The degrees
of freedom of an electromagnetic system are related to the capacity of a
transmission channel. In this paper, we investigate all these notions through
different case studies using full-wave electromagnetic simulations. The
capacity of a multi-antennas system is thus being analyzed on a physical
ground.
15:20 B07.6 TOWARD SYSTEM MODELING DEDICATED TO
FREQUENCY RECONFIGURABLE ANTENNAS
With
the recent evolution of wireless systems such as cognitive radio, new antennas
have to be developed to provide large bandwidth, compact size and especially
adaptive parameters for changing environments. The antennas are become more
again an essential part of wireless systems. They play a fundamental role both
in the propagation and also at a system level. New antennas models must be
developed being radically different from those currently available. The
potential of linear invariant time models associated to parametric approaches
to describe antennas is presented. Based on these approaches, a new method for
modeling reconfigurable antennas is proposed.
15:40 Tea/Coffee Break
16:00 B07.7 A LOW-PROFILE OMNIDIRECTIONAL PLANAR
ANTENNA WITH VERTICAL POLARIZATION
K. Sarabandi, J. Oh, The University of Michigan, Ann Arbor, United States
A
novel low-profile miniaturized antenna with vertical polarization and
omnidirectional radiation pattern employing two in-phase elements is presented.
The antenna operation is accomplished by substituting an impedance inverter
capacitor which produces the required 180 degree phase shifter with an open
stub. In this way, no conduction current in opposite direction to the radiating
pins is generated. The lateral dimension and height of the proposed antenna are
λ/8 and λ/40, respectively. A very high antenna gain of 0.5dBi is
obtained. Using the proposed design procedure, the performance of further
miniaturized antennas will be presented.
16:20 B07.8 MINIATURIZED TUNABLE MEANDERLINE LOADED
ANTENNA WITH Q-FACTOR APPROACHING THE LOWER BOUND
Having
a high-efficiency tunable antenna to cover wide band with good match is an
interesting topic, especially in the case when the physical size of the antenna
is too small. A novel spherical monopole antenna which has been miniaturized
through a couple of Meanderline sections has been presented in this paper. This
antenna, with maximum dimension of 0.05λ, has dual band operation with
independent frequency-tunable capability in 30 88 MHz frequency band. Thanks to
antenna geometry and Meanderline miniaturization technique, the exact Q-factor
of the antenna approaches the Thal lower bound.
16:40 B07.9 DESIGN AND OPTIMIZATION OF ULTRA-WIDEBAND
TEM HORN ANTENNAS FOR GPR APPLICATIONS
A. A. Jamali, R. Marklein, University of Kassel, Kassel, Germany
This
paper presents the design and optimization of UWB TEM horn antennas for GPR
applications. The numerical simulations of electromagnetic wave propagation are
performed in the time domain for a preliminary and modified TEM horn antenna.
The antennas have some properties which are not suitable for GPR applications.
These effects are reduced by optimization. The characteristic of the antennas
are computed. The optimized TEM horn antenna is then modeled with the typical
GPR environment with earth, and the hidden object inside the earth. The
presented antenna can be used in the GPR systems to detect and image buried
objects.
17:00 B07.10 GSM/UMTS DUAL POLARIZATION BASE STATION
ANTENNA DESIGN
Base
station antenna array is designed to cover frequency range from 1710 MHz to
2170 MHz. An entirely different antenna feed structure which consists of an
L-plate capacitive feed, is developed and a parasitic patch is optimized to
meet target design specifications. The antenna is +/- 45o dual polarization
with dedicated channels for each polarization. A prototype of the antenna
element is built and measured to corroborate simulation results. The antenna
array for BSA is designed to have an 18 dBi system gain with a VSWR less than
1.5 over the entire frequency band.
17:20 End of the Session
CHGBDJK – Solar Power Satellites and Wireless Power Transmission
Session Chairs: Naoki Shinohara, Kozo Hashimoto, Kristian Schlegel
Session CHGBDJK
Type Oral Presentation
Schedule Wednesday, August 17, 13:40-17:20
Room Dolmabahçe A
13:40 CHGBDJK.1 IMPROVEMENT OF A UBIQUITOUS POWER SOURCE
Ubiquitous
power source can wirelessly transmit power anywhere in a space. In order to
realize this system, we have examined an efficient power transmission system
which sends power to necessary places only based on direction of arrival
measurement. A simple in-phase transmission array is proposed and evaluated as
useful and efficient. This system can send power to multiple receivers. In
order to send the power to only necessary points, a pilot signal is sent from a
receiver. A low power system is manufactured and evaluated.
14:00 CHGBDJK.2 MICROWAVE ENERGY TRANSMISSION PROGRAM FOR
SSPS
Institute
for Unmanned Space Experiment Free Flyer, USEF, has been studying SSPS as
future electricity alternative energy source, which use 5.8GHz microwave energy
transmission technology. From 2009, USEF started new research and development
project of the Microwave Ground Wireless Power Transmission. This project
includes the study for high efficient and thin structured phased array antenna,
and the study for high efficient rectenna element. Also this project plans to
test ground wireless power transmission as a previous stage to the next space
experiment of SSPS. Outline and progress of this project are introduced.
14:20 CHGBDJK.3 MEETING THE CHALLENGES OF IMPLEMENTING
PORTABLE SPACE-BASED SOLAR POWER
F. E. Little, Texas A&M University, College Station, Texas, United States
A
space-based solar power system to supply power for disaster relief,
humanitarian aid or other temporary local electric power needs using a hybrid
laser/microwave wireless power transmission system is briefly described. A
space-to-ground experiment to validate retrodirective control of laser and
microwave power transmission beams that would use the International Space
Station as the in-space platform for the experimental apparatus is described.
14:40 CHGBDJK.4 ARRAY ANTENNA ARCHITECTURES FOR SOLAR
POWER SATELLITES AND WIRELESS POWER TRANSMISSION
G. Oliveri, P. Rocca, A. Massa, University of Trento, Trento, Italy
An
analytical technique for the synthesis of planar arrays for wireless power
transmission is proposed whose aim is to maximize the ratio between the power
collected at the receiver to the total transmitted power. The array weights are
optimized through an analytical methodology which formulates the synthesis
process as a generalized eigenvalue problem. The methodology can be applied for
arbitrary geometries of the transmitter array and whatever the rectenna shape.
A preliminary numerical validation is presented to assess the flexibility and
potentialities of the method.
15:00 CHGBDJK.5 ON THE MINIMIZATION OF SIDE-LOBES IN LARGE
ANTENNA ARRAYS FOR MICROWAVE POWER TRANSMISSION
Various
interesting properties a large antenna arrays with randomly, uniformly and
combined spacing of elements have been studied, especially the relationship
between the required number of elements and their appropriate spacing from one
viewpoint and the desired SLL, the aperture dimension, the beamwidth and TE
from the other. We propose a new unified approach in searching for reducing SLL
by exploiting the interaction of deterministic and stochastic workspaces of
proposed algorithms.
15:20 CHGBDJK.6 EXPERIMENTAL STUDY ON ONE-DIMENSIONAL
PHASED ARRAY ANTENNA INCLUDING LOSSY DIGITAL PHASE SHIFTERS FOR TRANSMITTING
POWER MAXIMIZATION
T. Mitani, Kyoto University, Uji, Japan; S. Tanaka, Y. Ebihara, Kyoto University, Kyoto, Japan
A
large-scale phased array antenna will be adopted as a microwave power
transmitter of solar power satellites. The objective of the present study is to
maximize transmitting power of a large-scale phased array antenna including
lossy digital phase shifters. In the present paper, we describe a newly
developed algorithm for transmitting power maximization, and demonstration
experiments of a one-dimensional 12-elements phased array antenna including
4-bit lossy digital phase shifters. We confirmed effectiveness of the developed
algorithm through the demonstration experiments as well as numerical
simulations.
15:40 Tea/Coffee Break
16:00 CHGBDJK.7 NEW RESEARCH FACILITIES OF PHASED ARRAY
AND ANECHOIC CHAMBER FOR SPS
N. Shinohara, Kyoto University, Kyoto, Japan
A
Space Solar Power Satellite/Station (SPS) requires high efficiency and low cost
phased array for a microwave power transmission from the SPS to ground. For the
phased array of the SPS, we have developed new phased array research facility,
new rectenna (rectifying antenna) array research facility, and a special
anechoic chamber for the SPS experiment in Kyoto University in FY2010. In this
paper, I show the characteristics of the new phased array and rectenna array. I
also introduce the new anechoic chamber for the SPS in Kyoto University.
16:20 CHGBDJK.8 MW WPT FOR HAPS AND SPS: CONCEPTS, EMI AND
BIOLOGICAL HAZARDS ISSUES
J. Gavan, S. Tapuchi, SCE, Ashdod, Israel
The
long distances Microwave (MW) Wireless Power Transmission (WPT) concepts are
followed by the presentation of high Altitude Platforms (HAPS) principles.
Stratospheric HAPS operation requiring up to a few hundreds kW of electrical
power is limited by long sun eclipses. The realization of terrestrial MW WPT
systems feeding HAPS could be useful for their long duration operation and for
the preliminary tests of more complex and power demanding Solar Power
Satellites (SPS) systems. Electro Magnetic Interference (EMI) and biological
hazards issues will be discussed for selected frequencies and compared for
terrestrial, HAPS and SPS long range MW WPT systems.
16:40 CHGBDJK.9 IMPACT TO THE RADIO ASTRONOMY BY THE
INTERFERENCE CAUSED BY THE SOLAR POWER SATELLITE SYSTEMS
M. Ohishi, National Astronomical Observatory of Japan, Tokyo, Japan
We
have conducted a preliminary study to assess interference caused by a SPS to
radio astronomy observations, and show that the SPS that is currently planned
is highly unlikely to coexist with radio astronomy observations.
17:00 CHGBDJK.10 CYLINDRICAL DIELECTRIC RESONATOR ANTENNAS
FED BY A STAIR SLOT IN THE GROUND PLANE OF A MICROSTRIPLINE
A
novel coupling scheme to cylindrical dielectric resonator antenna is proposed
and investigated. In particular, coupling to the resonator is achieved by
simple slot firstly and a stair slot secondly exited by a microstrip line. The
objectives of this change are to maximize the coupling, increase a gain and
miniaturize the structure antenna, achieve resonance at the desired frequency.
An approximate and quick design approach is given followed by more accurate
design and analysis using commercial software. The antenna was fabricated and
tested. Measurements match well with simulation results.
17:20 End of the Session
DT – RFID Technology and Applications
Session Chair: Franz Kaertner
Session DT
Type Oral Presentation
Schedule Wednesday, August 17, 13:40-14:40
Room Dolmabahçe B
13:40 DT.1 INKJET-PRINTED PAPER/POLYMER-BASED RFID
AND WIRELESS SENSOR NODES
In
this talk, inkjet-printed flexible antennas, RF electronics and sensors
fabricated on paper and other polymer (e.g.LCP)substrates are introduced as a
system-level solution for ultra-low-cost mass production of UHF Radio Frequency
Identification (RFID) Tags and Wireless Sensor Nodes (WSN) in an approach that
could be easily extended to other microwave and wireless applications. Plus, we
will discuss issues concerning the power sources of "near-perpetual"
RF modules and the first examples of the integration of inkjet-printed
nanotechnology-based (e.g.CNT) sensors on paper and organic substrates.
14:40 End of the Session
EB – Electromagnetic Modelling for EMC
Session Chairs: Levent Gurel, A. Tijhuis
Session EB
Type Oral Presentation
Schedule Wednesday, August 17, 13:40-17:20
Room Galata
13:40 EB.1 MULTI-SCALE MODELLING IN THE TIME-DOMAIN
FOR EMC STUDIES
C. Christopoulos, University of Nottingham, Nottingham, United Kingdom
The
paper addresses a particular feature of EMC, namely the presence of multi-scale
objects, which make it a challenging modelling problem. By a multi-scale
problem we mean the presence in the same solution space of features which are
electrically small (relatively to the wavelength) and electrically large. The
brute force approach requiring faster and larger computers has its limits. An
innovative modelling approach based on hybrid techniques is needed. The
embedding of local solutions around fine features in the form of macro-models
and the hybridization of structured and unstructured meshes are described.
14:00 EB.2 EFFICIENT STOCHASTIC EMC/EMI ANALYSIS
USING HDMR-GENERATED SURROGATE MODELS
This
paper presents an extension to generalized polynomial chaos (gPC) based
stochastic collocation methods (SC) for statistically characterizing EMC/EMI
phenomena. The proposed extension leverages high dimensional model
representation (HDMR) expansions to approximate EMC/EMI observables in terms of
finite sums of component functions. The HDMR expansion is constructed by
iteratively selecting significant component functions, each of which is
approximated by an h-adaptive SC-gPC method. The proposed extension is capable
of statistically characterizing rapidly varying/smooth observables pertinent to
EMC/EMI analysis characterized by a large number of uncertain parameters.
14:20 EB.3 EMI/EMC MODELING OF PACKAGED ELECTRONICS:
CHALLENGES AND OPPORTUNITIES
A. C. Cangellaris, J. Russer, University of Illinois, Urbana-Champaign, Urbana, IL, United States
The
complexity of EMI/EMC modeling at the system level of multifunctional
electronics necessitates the use of approximations in the development of a
manageable computer model. Such approximations can be interpreted in terms of
geometric, material, and layout variability. This variability calls for
methodologies and tools for predictive component and system performance and
functionality assessment in the presence of uncertainty. Such modeling
capability is not available today. This paper explores the opportunities for
and potential benefits from the development of such modeling capability in
support of EMI/EMC modeling for noise-aware computer-aided integration of
multi-functional electronic systems.
14:40 EB.4 HIGHER ORDER FULLY OVERLAPPING DOMAIN
DECOMPOSITION METHOD FOR EMI/EMC MODELING
T. Peng, K. Sertel, J. L. Volakis, The Ohio State University, Columbus, United States
We
propose a fully overlapping domain decomposition method for the analysis of
small radiating/receiving features situated in large enclosures for EMI/EMC
analysis. The proposed method decouples the relatively dense finite element
mesh (representing the small scale RF environment with high fidelity), from the
coarse background mesh modeling propagation and coupling effects with
enclosures and nearby cable bundles. This overlapping decomposi- tion allows
for unstructured meshing of the small features within large domains, providing
great flexibility in modeling multi-scale electromagnetic environments. We also
demonstrate a higher-order version of the proposed method to further improve
computational efficiency.
15:00 EB.5 A WIDEBAND FAST INTEGRAL EQUATION SOLVER
COMBINING MULTILEVEL FAST MULTIPOLE AND MULTILEVEL GREENS FUNCTION
INTERPOLATION METHOD WITH FAST FOURIER TRANSFORM ACCELERATION
D. T. Schobert, T. F. Eibert, TU Muenchen, Munich, Germany
A
wideband fast integral solver employing a fast Fourier transform accelerated
multilevel Greens function interpolation method (MLIPFFT) combined with the
multilevel fast multipole method (MLFMM) is presented. On fine levels of the
employed oct-tree structure, the low frequency stable MLIPFFT is utilized. At a
certain wavelength dependent threshold for the box size, the interpolation
point based representation of the MLIPFFT is converted into its k-space
representation suitable for an MLFMM. On the coarser levels, MLFMM translations
are used then, where the MLIPFFT becomes less efficient. The functionality of
this hybrid algorithm is demonstrated in an example.
15:20 EB.6 A LARGE DOMAIN COMPLETE BASIS FUNCTION SET
FOR CURVED SURFACES
This
paper presents a new set of complete basis functions for curved scatterers
derived by the generalization of the recently introduced Linear Phase Functions
in the parametric space. This set is able to represent the field radiated by
any current on a curved surface in a nonredundant way. The procedure has been
validated through comparison with standard RWG based MoM solution.
15:40 Tea/Coffee Break
16:00 EB.7 ON ANALYTIC EXPRESSIONS FOR FAST
ESTIMATION OF COUPLING BETWEEN ELECTRICALLY SHORT THIN-WIRE ANTENNAS WITHIN
CAVITIES
F. Gronwald, Hamburg University of Technology, Hamburg, Germany
Method
of moment solutions for thin-wire antenna currents can turn to analytic
solutions if the antennas are electrically small. This observation is useful
for the analysis of interior problems of Electromagnetic Compatibility when
transmitting and receiving thin-wire antennas serve to model electromagnetic
sources and victims within a resonating environment. The analytic solutions allow
fast evaluation of corresponding couplings but also are of limited accuracy.
This is exemplified by the example of two coupled antennas within a rectangular
cavity where coupling results between an analytical solution and an actual
method of moment solution are compared.
16:20 EB.8 TOWARDS A FIRST TIME RIGHT DESIGN OF THE
COMMON MODE CHOKE
There
is a need for an analytical model of the EMI filter relating its designable
parameters to its final performances in the circuit. The final goal of the
model is to support a first time right design of the common mode choke. A new
equivalent circuit is proposed where impedances are related to the designable
parameters of the choke. The actual performances of the choke can be evaluated
via a modification factor of the common mode current. Sensitivities and deviation
studies give additional insight on the behavior of the filter once it is placed
in the practical system.
16:40 EB.9 A SHORT INVESTIGATION IN THE OLD WALL
STIRRING METHOD FOR REVERBERATING CHAMBERS
J. Nijenhuis, Comtest, Zoeterwoude, Netherlands
An
old method of stirring a reverberating chamber, shifting a wall, has been
simulated and compared with the common stirring methods. The main advantage is
that there is no stirrer that has to be placed away from the walls and so in e
ect is placed in the middle of the chamber. A stirred volume of 10 % can easily
be achieved with only one stirrer, so only one actuator and maintaining a large
working volume. The chamber is well shielded by building the moving wall inside
the shielded box and no stirrer means less surface so a higher Q factor.
17:00 EB.10 TIME-DOMAIN INVESTIGATION ON RIBBON
CABLE-INDUCED TRANSIENT COUPLING INTO ENCLOSURE
A
hybrid time-domain method is proposed for characterizing electromagnetic
interference (EMI) signals in some composite structures with two-wire ribbon
cable transmission lines, metallic enclosures, and even lumped active devices
involved. In order to fast capture the inner EMI signals induced, Finite
Difference Time-Domain (FDTD), and multi-conductor transmission lines (MTL)
methods are combined together and implemented successfully. Numerical
investigation is carried out to show the induced current, voltage, and
enclosure shielding effectiveness of some practical geometry with metallic
enclosure and ribbon cables, and even a cable networks.
17:20 End of the Session
F06 – Remote Sensing of Oceans, Cryosphere and Related Topics
Session Chair: Albin Gasiewski
Session F06
Type Oral Presentation
Schedule Wednesday, August 17, 13:40-17:20
Room Haliç
13:40 F06.1 SENSITIVITY ANALYSIS OF MICROWAVE
BACKSCATTERING AND EMISSION TO SNOW WATER EQUIVALENT: SYNERGY OF DUAL SENSOR
OBSERVATIONS
A
sensitivity analysis of emission and backscattering to snow water equivalent
(SWE) is performed using a two-layer Dense Medium Radiative Transfer Model
implemented for both active and passive case. To evaluate the potential of the
Cosmo-Skymed mission, the study is focussed on X band sensors. Simulations have
shown an appreciable sensitivity of X-band backscattering/emission to dry snow
for SWE higher than 70-100 mm and relatively high values of snow density and
crystal dimensions. Experimental data from CosmoSkymed and ground based
radiometers confirmed these results. Synergetic combination of active/passive
sensors is suggested for operational use.
14:00 F06.2 A UNIFIED MICROWAVE RADIATIVE TRANSFER
MODEL WITH JACOBIAN FOR GENERAL PLANAR STRATIFIED MEDIA
M. Tian, A. J. Gasiewski, University of Colorado, Boulder, Boulder, United States
A
unified microwave radiative transfer (UMRT) model is presented for computing
the thermal radiation from geophysical media comprised of planar multilayer
spherical scatterers of arbitrary electrical size and density. UMRT employs
discrete ordinate-eigenanalysis to solve the vector radiative transfer
equation. Importantly, UMRT inherits the symmetrization, analytical
diagonalization, and factorization techniques from the discrete ordinate
tangent linear radiative transfer (DOTLRT) model devised by Voronovich et al.,
to ensure accuracy, numerical stability, and computational efficiency, along
with Jacobian capability. However UMRT extends the applicability of DOTLRT by
including the dense media radiative transfer theory and linear temperature
profiles within slabs.
14:20 F06.3 ELECTROMAGNETIC SCATTERING FROM
TWO-SCATTERERS USING THE EXTENDED PROPAGATION-INSIDE-LAYER EXPANSION METHOD
In
this paper, the electromagnetic scattering from two scatterers is analyzed from
a rigorous integral formulation solved by the method of moments (MoM). G.
Kubicke has recently developed the E-PILE (Extended Propagation-Inside-Layer
Expansion) method to calculate the scattering from an object above a rough
surface for a two-dimensional problem. This method allows us to calculate
separately and exactly the interactions between the object and the rough
surface. The purpose of this paper is to extend the E-PILE method to a
three-dimensional problem.
14:40 F06.4 MODELING OF 2D RADAR BACKSCATTERING FROM
OIL FILMS ON SEA SURFACES
This
paper presents the modeling of the radar backscattering from clean and
contaminated seas for two-dimensional (2D) problems. Contaminated seas considered
here are made up of homogeneous oil films on sea surfaces. In practice, these
films being thin, they are assumed to form two parallel interfaces. In order to
deal with this two-layer problem, a so-called "thin-layer" approach
is tested and compared with a reference numerical method. Also, a more basic
approach is tested for comparison. Last, by comparison with the clean sea case,
the contaminated sea detection is tested with respect to the observation angle.
15:00 F06.5 VHF RADAR STUDIES OF THE MIGRATING AND
NONMIGRATING DIURNAL AND SEMIDIURNAL TIDES OVER A TROPICAL AND AN EQUATORIAL
STATION
VHF
radar measurements of winds are utilized to study the diurnal and semi-diurnal
tides over Gadanki and Kotatabang. The tidal amplitudes exhibit maxima in UTLS
region during June-September (Gadanki) and during March and September
(Kotatabang). The vertical wavelength is 3-5km (Gadanki) and 25-30km
(Kotatabang), which reveal the existence of nonmigrating and migrating tides,
respectively. Brightness temperature shows that over Gadanki(deep) and
Kotatabang (shallow) convective clouds. Latent-heat release by deep-clouds is
found to be the main source mechanism for nonmigrating tides. This study brings
out the differences in tides over equator and low latitude.
15:20 F06.6 ANALYTICAL PREDICTION OF THE POLARIZED
DOPPLER SPECTRUM FROM NONLINEAR OCEAN SURFACE AT MICROWAVE FREQUENCY
This
poster depicts the use of combined hydrodynamic and electromagnetic analytical
models for the simulation of the polarized ocean Doppler spectrum at microwave
frequencies. We consider linear and weakly nonlinear sea surfaces after the
Choppy Wave Model and incorporate them in the Weighted Curvature Approximation
surface scattering method. Statistical expressions are derived, for the Doppler
spectrum as well as for its central frequency and width. Results compare
favorably with rigorous numerical computations for one-dimensional surfaces
published in the literature. The simplicity of the analytical models provide a
valuable tool for the Doppler analysis of two-dimensional sea-surfaces.
15:40 Tea/Coffee Break
16:00 F06.7 A METHOD OF CALCULATION OF ELECTRON
DENSITY PROFILES FROM H'(F) TRACES OF VERTICAL SOUNDING
O. A. Laryunin, V. I. Kurkin, Institute of Solar-Terrestrial Physics, Irkutsk, Russian Federation
In
this paper we describe a method developed at ISTP SB RAS to calculate the
electron density profile in the anisotropic ionosphere from vertical sounding
data. The input data in the problem provided are magnetic inclination and h(f)
traces for ordinary and extraordinary wave. The output data are the electron
density profile (or the plasma frequency profile). The program implementing
this algorithm has been tested for a great number of model profiles, and the
profiles calculated provide a coincidence accurate enough with the original
ones except a valley region discrepancy inevitable for any approximating
method.
16:20 F06.8 COMPARISON OF NO2 VERTICAL PROFILES FROM
SATELLITE AND GROUND BASED MEASUREMENTS OVER ANTARCTICA
The
Intercomparison of nitrogen dioxide (NO2) vertical profiles, derived from the
satellite based HALogen Occultation Experiment (HALOE) measurements and from
the ground based UV-VIS spectrometer GASCOD (Gas Analyzer Spectrometer
Correlating Optical Differences) observations at the Mario Zucchelli Station
(MZS), in Antarctica, are done for the first time. It is shown here that both
datasets are in good agreement showing the same features in terms of magnitude,
profile structure, and temporal variations.
16:40 F06.9 INVESTIGATION OF RADIO FREQUENCY
INTERFERENCE AT L-BAND USING DATA FROM AIRBORNE HUT-2D RADIOMETER AND
SPACEBORNE SMOS RADIOMETER
Aperture
synthesis technique in L-band radiometry is effective in producing good quality
data with reasonable ground resolution. However, since the technique is based
on using numerous individual receivers, from which the output signals are
correlated, the technique is sensitive to man-made interfering signal sources.
It is important to identify existing sources of Radio Frequency Interference
(RFI) to ensure good quality data. This paper describes the work done in Aalto
University using available SMOS data and Aalto University's L-band aperture
synthesis airborne radiometer (HUT-2D) data collected during the SMOS rehearsal
campaigns and national campaigns.
17:00 F06.10 SIMULTANEOUS RETRIEVAL OF SEA SURFACE WIND
SPEED AND SEA SURFACE TEMPERATURE FROM A MULTI-FREQUENCY SCANNING MICROWAVE
RADIOMETER
D. Swain, National Remote Sensing Centre, ISRO, Hyderabad, Andhra Pradesh, India
Derivation
of geophysical parameters from satellite measured brightness-temperature (TB)
is an important aspect of satellite remote sensing. In this work, an Artificial
Neural Network model has been attempted to simultaneously obtain sea surface
wind speed (WS) and sea surface temperature (SST) utilizing 8 channels TB
(including dual polarizations) of Multifrequency Scanning Microwave Radiometer
on board Indian Remote Sensing Satellite (IRS-P4) and deep sea ocean buoys in
the North Indian Ocean. The ANN obtained values are then compared with actual
in situ observations, concluding that the ANN model provides good estimates of
WS and SST, within acceptable errors.
17:20 End of the Session
G06 – Distributed Ground and Space-based Observatories for Space Weather Studies
Session Chairs: Patricia Doherty, Anthea Coster, Lee-Anne McKinnell
Session G06
Type Oral Presentation
Schedule Wednesday, August 17, 13:40-17:00
Room Topkapi A
13:40 G06.1 COORDINATED ARRAYS OF DISTRIBUTED
INSTRUMENTS: A NEW WINDOW ON GEOSPACE SCIENCE AND SPACE WEATHER EFFECTS
J. C. Foster, MIT Haystack Observatory, Westford, MA, United States
MIT
Haystack Observatory, Westford, MA, United States Geospace is a complex coupled
system, and arrays of ground and space-based instrumentation are needed to
monitor and understand geospace characteristics and dynamics on a global,
real-time basis. Several geospace research topics requiring a system
perspective and coordinated distributed observations are discussed. Both the
CEDAR 2010 Strategic Plan and the DASI initiative (Distributed Arrays of
Scientific Instruments) embrace these concepts. A phased approach to DASI,
combining existing instrument arrays to address system-science research topics,
is an initial step toward providing the needed global geospace coverage.
14:00 G06.2 IDENTIFICATION OF TIDS AND PLASMA
DEPLETIONS USING THE LISN OBSERVATORY
C. E. Valladares, P. H. Doherty, Boston College, Chestnut Hill, United States
The
Low-latitude Ionospheric Sensor Network (LISN) is a distributed observatory
that includes GPS receivers, magnetometers and ionosondes deployed in South
America. Continuous values of TEC measured by 127 GPS receivers over South
America have been used to construct maps of TEC. And, to identify TEC
perturbations that are associated with the passage of traveling ionospheric
disturbances (TID) and plasma depletions. This presentation will show initial
results on the seasonal/longitudinal distributions of TEC depletions over South
America and the relationship of these distributions with the variability of TEC
and the occurrence of TEC perturbations associated with gravity waves.
14:20 G06.3 CO-LOCATED SPACE WEATHER RADAR STUDIES
OVER SOUTHERN AFRICA
Recently
attention has been given to increasing the geophysical infrastructure within
the African region with particular emphasis on data collection for the
enhancement of our knowledge of events that result from adverse Space Weather.
South Africa continues to contribute to this effort by expanding its own
networks, assisting networks in other African countries, and training young
researchers from Africa. At least 4 field sites in South Africa host co-located
radar systems. This paper will demonstrate the ability to enhance scientific
investigation of Space Weather events over South Africa using co-located radar
systems.
14:40 G06.4 HIGH-LATITUDE GPS TEC CHANGES ASSOCIATED
WITH SUDDEN MAGNETOSPHERIC COMPRESSION
Using
ionospheric total electron content (TEC) measured by Global Positioning System
(GPS) receivers of the Canadian High Arctic Network (CHAIN), we provide clear evidence
for a systematic and propagating TEC enhancement produced by the compression of
the magnetosphere due to a sudden increase in the solar wind dynamic pressure.
Application of a GPS triangulation technique revealed that the TEC chnages
propagated with a speed of ~ 6 km/s near noon and ~ 7 km/s in the pre-noon
sectors. This is consistent with the scenario of increased ionospheric
convection due to the magnetospheric compression.
15:00 G06.5 CONCURRENT OBSERVATIONS OF UPPER
THERMOSPHERIC NEUTRAL WIND AND PLASMA CONVECTION AT HIGH LATITUDES OF BOTH
HEMISPHERES
We
present statistical studies of both the high-latitude ionospheric convection
and the upper thermospheric circulation patterns obtained from almost a decade
of measurements starting in 2001 of the electron drift instrument (EDI) on
board the Cluster satellites and an accelerometer on board the CHAMP spacecraft,
respectively. We obtained both regular upper thermospheric wind vorticity and
ionospheric plasma drift pattern according to the various IMF conditions in a
statistical average sense. The results show some prominent asymmetries between
the two hemispheres, which are mainly due to different geographic-geomagnetic
offsets and can partly be attributed to differing ionospheric conductivities
15:20 G06.6 INTERCEPTED SIGNALS FOR IONOSPHERIC
SCIENCE
The
Intercepted Signals for Ionospheric Science (ISIS) Array is a coherent software
radio network that has recently been deployed. Nodes of this array are
installed along the northern United States, and the array is well positioned
for the observation of Space Weather in the mid-latitude Geospace environment.
We will describe the design of the array, its status, and give examples of
observations. We will present coherent scatter observations of E-region
irregularities during the Geomagnetic storm of August 3-5, 2010. To conclude we
will provide an overview of future directions for distributed software radio
sensor networks.
15:40 Tea/Coffee Break
16:00 G06.7 THE SOUTH AMERICA VLF NETWORK (SAVNET):
PROVIDING NEW GROUND-BASED DIAGNOSTICS OF SPACE WEATHER CONDITIONS
J.-P. Raulin, Universidade Presbiteriana Mackenzie, So Paulo, SP, Brazil
Wereport
recent results obtained by the South America VLF Network (SAVNET). The use of
the VLF technique by tracking subionospheric propagation anomalies appears as a
very promising tool to study various aspects of Space Weather disturbances. On
long timescales it is possible to indirectly monitor the solar Lyman-a
radiation along the solar cycles. Short time phenomena like solar explosive
events can be observed with 100% probability, even for the small intensity
events. Finally, the same technique is relevant to study the low ionospheric
perturbations caused by geomagnetic storms on typical timescales of a day to
few days.
16:20 G06.8 EQUATORIAL SCINTILLATION CHARACTERISTICS
DURING SOLAR MINIMUM: OBSERVATIONS FROM THE SCINDA NETWORK
The
Communication/Navigation Outage Forecast System (C/NOFS) satellite was launched
in April 2008 for the purpose of specifying and forecasting equatorial
ionospheric scintillation. For the first two years on orbit the satellite
operated in a period of very low solar flux and observed a significant
occurrence of irregularities in the post-midnight timeframe while detecting an
unexpectedly low level of disturbances in the post-sunset sector prior to
midnight. Here we investigate the occurrence of irregularities as observed from
the SCINDA network of ground sensors, comparing and contrasting differences and
similarities.
16:40 G06.9 GROUND-BASED INSTRUMENTATIONS IN AFRICAN
AND THEIR SCIENTIFIC AND SOCIETAL BENEFITS TO THE REGION
E. Yizengaw, Institute for Scientific Research, Chestnut Hill, United States
Satellites
observations indicated that the equatorial ionosphere in the African sector
responds differently than other sectors. To investigate in detail, during the
past couple of years very limited instruments have been either deployed in the
region or in process. However, to understand the most dynamic ionospheric
irregularities in the region, those few instruments are far from enough. By
combining the multi instrument independent observations, this paper will show a
cause and effect space weather impact in the region for the first time. The
paper will present the ongoing extensive activities on the possibilities of
placing an equatorial ISR in Africa.
17:00 End of the Session
HG2 – Radio Sounding in Ionospheres and Magnetospheres and Associated Plasma Phenomena II
Session Chairs: Robert Benson, Bodo Reinisch, Gordon James, Vikas Sonwalkar
Session HG2
Type Oral Presentation
Schedule Wednesday, August 17, 13:40-17:20
Room Topkapi B
13:40 HG2.1 VARIATION OF THE ELECTRON DENSITY IN THE
HIGH-LATITUDE TOPSIDE IONOSPHERE DURING LARGE MAGNETIC STORMS
We
investigate the response of the high latitude topside ionosphere to large
geomagnetic storms. We employ electron-density profiles, derived from the
Alouette and ISIS topside sounder satellites, available from http://nssdc.gsfc.nasa.gov/space/isis/isis-status.html
which also describes a recent data restoration project. The focus was on the
20-yr interval from 1965 to 1985 when both solar-wind and Alouette/ISIS
topside-sounder data are potentially available. Several case studies were
investigated and some showed significant Ne enhancements in the high-latitude
topside ionosphere. We present and discuss these cases in detail.
14:00 HG2.2 GETTING NEW SCIENCE FROM OLD TOPSIDE
SOUNDER DATA WITH NEW ANALYSIS TECHNIQUE
The
Alouette/ISIS topside sounder satellites recorded a great wealth of information
about the topside ionosphere during their long period of operations from 1962
to 1990. So much though that only a small percentage was analyzed during the
mission lifetime. A data restoration effort first digitized the analog data and
then developed the TOPIST software for automated inversion of the ionograms to
electron density profiles. We present the data base established by this data
restoration project and discuss science results obtained with these data. The
ISIS project homepage is at
http://nssdc.gsfc.nasa.gov/space/isis/isis-status.html.
14:20 HG2.3 SPACE PLASMA ENVIRONMENT AT HIGH AND POLAR
LATITUDES BY THE COSMOS 1809 SATELLITE TOPSIDE SOUNDER DATA
The
paper presents results of Cosmos 1809 satellite topside sounder data
processing. Analogous records of topside ionograms collected during the
icebreaker Sibir cruise to the North Pole in 1987 are transformed in the
digital ionograms dataset for the more than 100 cross-pole passes (more than
8000 ionograms). For different plasma conditions (fp>fhe and fp<fhe) we
demonstrate the power of topside sounding using not only traditional critical
frequency and vertical profile parameters but also the plasma resonances
distribution, natural emissions registered both on ionograms and on dynamic
spectrograms created from AGC records which permit to map magnetospheric structures.
14:40 HG2.4 SPACE-BORNE RADIO-SOUNDING INVESTIGATIONS
FACILITATED BY THE VIRTUAL WAVE OBSERVATORY (VWO)
The
goal of the Virtual Wave Observatory (VWO) is to provide user-friendly access
to heliophysics wave data. While the VWO initially emphasized data from passive
receivers, it can also be used to access active sounder data sets. Here we use
examples from some half-million Alouette-2, ISIS-1, and ISIS-2 digital
topside-sounder ionograms to demonstrate the desirability of such access to the
actual ionograms for investigations of both natural and sounder-stimulated
plasma-wave phenomena. By this demonstration, we wish to encourage
investigators to make other valuable space-borne sounder data sets accessible
via the VWO.
15:00 HG2.5 HIGH FREQUENCY DIAGNOSTICS ON THE
CORONAS-I SATELLITE
A. Kiraga, Space Research Center PolishAcadamy of Science, Warsaw, Poland
Quasi
simultaneous data on High Frequency (HF) noise, antenna impedance and topside
sounder were registered onboard the CORONAS-I satellite which operated in a
nearly circular orbit of 500 km altitude and 82.5 deg inclination. Relevant
details of the instrument operation are presented. We show the relevance of the
equivalent circuit approach for identification of plasma density signatures in
the noise and impedance data. Examples of onboard reduction of topside sounder
data are presented. Examples of electron-density signatures extracted by
onboard processing of impedance data and topside sounder data are shown. The
advantages of integrated diagnostics for monitoring the plasma density are
pointed out.
15:20 HG2.6 EMISSION AND RECEPTION OF BERNSTEIN WAVES
IN THE OEDIPUS-C EXPERIMENT