COST IC1102
4th WG Meeting & Technical Workshop
Thessaloniki, May 22-24, 2013
Abstracts
Wednesday, May 22, 2013
16.00 – 19.00
MC Meeting
Mediterranean Palace Hotel
20.00 – 22.30
MC Dinner (self paid)
Makedonia Palace Hotel
09.00 – 09.15
Registrations - Opening
09.15 – 09.50
WG1 Invited Talk
Chair: Marta Martinez
Addressing Small Cells Challenges through Advanced
Communication Techniques
Dr. Panagiotis I. Dallas
INTRACOM Telecom S.A., Greece
Abstract: The evolution of 4G networks and the corresponding economics
necessitate the transformation of LTE macro cells to zero-footprint cells at
the street level, called small cells. The rise of a small-cell grid networks,
mainly localized wherever there is economic interest for capacity
“injection” introduces new backhaul requirements. Among the other
backhauling techniques, the radio ones either Point-to-Point or Point-toMultiPoint will prevail. INTRACOM Telecom extending its wireless backhaul
portfolio introduced the “StreetNodeTM”. “StreetNodeTM” is an ultracompact, “everything-in-a-box”, product based on Software Define Radio
and an auto-aligned antenna with 3D capability alignment. In this arena, a
new era of challenges has been prescribed and they establish the
framework for a potential cooperation between academy and industry.
Mediterranean Palace Hotel
Thursday, May 23, 2013
Page 1 of 23
09.50 – 10.30
WG2 presentations
Chair: Milos Mazanek
09.50 – 10.10
THz Micromachined High-gain Antennas
Alexandros Feresidis, Michael J. Lancaster, and Peter S. Hall
School of Electrical, Electronic and Computer Engineering University of
Birmingham, Birmingham, B15 2TT, UK
Abstract: Terahertz (THz) frequencies offer new opportunities for
communications, sensing and imagingapplications. These include multiGigabit/s short range communication links as well as highly resolution
sensing and imaging, such as medical and security scanning systems.
However, high performance THz components are yet to be developed for
efficient, compact and reliable systems to be produced. An important
requirement for developing viable wireless communication systems at the
emerging THz bands is the use of high gain antennas which will
significantly improve the overall system gain and enhance the signal-tonoiseratio. In addition to communications, THz high-gain and highefficiency antennas are a major requirement in a number of sensing and
imaging applications.
Reflector-based antennas and horn antennas have been used at higher
mm-wave frequencies with good radiation performance. However, planar
antennas are required for compact systems. In addition, planar antennas
are readily compatible with micromachining techniques which lead to lowcost fabrication. In this contribution, we present planar high-gain antennas
at 300GHz developed using micromachined metalized SU8 polymer. A 1-D
slotted waveguide antenna is demonstrated using an SU-8-based
fabrication technique at 300 GHz. It is believed to be the highest operation
frequency ever demonstrated using such a slot array structure. In addition,
a 2-D high gain periodic leaky-wave antenna is presented based on the
same fabrication process and achieving a gain of about 20dBi.
10.10 – 10.30
Mediterranean Palace Hotel
Thursday, May 23, 2013
Comparative study of Rotman lens implemented by different
technologies in V band
Michal Pokorný1, Zbyněk Raida1, Jussi Säily2, and Jouko Aurinsalo2
1
Department of Radio Electronics Brno University of Technology, Brno,
Czech Republic
2
Sensing and Wireless Devices research group, VTT Technical Research
Centre of Finland
Abstract: This contribution is targeted on the investigation of the Rotman
lens performance at V band. The talk will be focused on a comparison of
the specific Rotman lens design implemented by various technologies. The
numerical results for microstrip and SIW implementations in thick and thin
substrate technologies will be provided. The issues of the lens losses and
fabrication difficulties will be also discussed. The described work is part of
Page 2 of 23
Thursday, May 23, 2013
10.30 – 11.00
Coffee Break
11.00 – 12.40
WG2 presentations
Chair: Milos Mazanek
11.00 – 11.20
Dielectric Rod Waveguide Antennas for Photomixer-Based Terahertz
Power Generation
Alejandro Rivera Lavado1, Luis Enrique García Muñoz1, Andrey Generalov2,
Sascha Preu3, Gottfried Döhler3, Dmitri Lioubtchenko2, Stefan Malzer3,
Antti V. Räisänen2, and Daniel Segovia Vargas1
1
Universidad Carlos III de Madrid. Departamento de Teoría de la Señal y
Comunicaciones, Leganés, Madrid, Spain
2
Aalto University School of Electrical Engineering, Finland
3
Friedrich-Alexander - Universität Erlangen-Nürnberg, Erlangen, Germany
Abstract: In this contribution the use of dielectric rod waveguide antenna is
proposed in order to avoid losses due to diffusion of the terahertz
generated power into the substrate. A preliminary radiation pattern
measurement is shown.
11.20 – 11.40
On the bandwidth limits in modern day low profile multilayer microwave
antennas generating dual circular or quadruple polarizations
Pawel Kabacik, Arkadiusz Byndas, Mariusz Hofman, and Przemyslaw Gorski
Institute of Telecommunications, Teleinformatics and Acoustics, Wroclaw
University of Technology, 50-370 Poland
Mediterranean Palace Hotel
the cooperation frame between Brno University of Technology and VTT
Technical Research Centre of Finland.
Abstract: To versatile, integrated, and signal-aware technologies for
antennas, enhancing performance in terms of the following parameters
often highlights major efforts in R&D of such microwave antennas:
(i) accomplishing broad bandwidth,
(ii) use of antenna manufacturing with the large scale of integration,
combining antenna elements and their feed networks into a single module,
(iii) at least dual-polarization operation, often with dual circular
polarizations as the minimum,
(iv) state-of-the-art in antenna miniaturization by its volume, low-profile,
(v) capabilities to make antenna conforming to other than planar surfaces.
Furthermore, the antenna become of the highest desire to practical
applications when it can be used in harsh environment, particularly under
broad range of temperatures and high humidity. Antennas on which that
technical contribution is focused, are typically 6 to 20 mm thick,
concurrently generate two polarizations and are able to sustain more than
250 deg C of temperature variations.
In this technical presentation, we will address antenna technology most
preferable applicable to microwave frequency ranges from UHV to Ka
Page 3 of 23
Thursday, May 23, 2013
bands. The conclusions are drawn with results of our extensive studies into
multilayer antenna panels operating with two frequency ranges or two
circular (or linear) polarizations. Our discussion of antenna bandwidth
performance refers to all major antenna parameters: impedance match
bandwidth, isolation between various polarizations, gain and efficiency,
axial ratio and radiation pattern examined in the spherical format.
Testing Backscatter Sensor Networks at the Power-limited Regime with
Commodity Software-Defined Radio: Reporting Achieved Communication
Ranges
Aggelos Bletsas1, John Kimionis1, and John N. Sahalos2
1
Technical Univ. of Crete, Greece
2
Univ. of Nicosia, Cyprus
Abstract: This work puts forth bistatic backscatter radio for low-bit rate
environmental sensing applications that require extended communication
ranges. In sharp contrast to common radio frequency identification (RFID)
systems, the carrier emitting part is detached from the receiving part of the
reader, enabling the co-existence of multiple ultra-low cost carrier emitters.
Specifically, this work experimentally evaluates field coverage extension
with semi-passive backscatter-enabled sensors, compared to conventional
monostatic backscatter radio architectures, typically seen in passive RFID
systems. For asymmetric outdoor scenarios with 2-4m distance between
carrier emitter and sensor, communication range on the order of 120m
between sensor and reader is achieved, at 13dBm carrier emitter power
and 2-5% bit-error-rate (BER). For symmetric outdoor scenarios with 25m
distance between carrier emitter and sensor, communication range on the
order of 25m between sensor and reader is achieved, at 13dBm carrier
emitter power and 2% BER. The idiosyncrasies of bistatic, low-bit rate
backscatter radio are highlighted and contrasted to conventional
monostatic architectures, with emphasis on detection and processing
techniques for commodity, low-cost software-defined receivers (SDR). This
work may potential open new research avenues for ultra-low cost
environmental sensing.
12.00 - 12.20
Mediterranean Palace Hotel
11.40 – 12.00
Metasurfing Leaky Wave Antennas
Ioannis Iliopoulos1,2, Marc Esquius Morote1, Juan R. Mosig1, and
Traianos V. Yioultsis2
1
Laboratoire d’Electromagnétisme et d’Acoustique, École Polytechnique
Fédérale de Lausanne, 1015 Lausanne, Switzerland
2
Dept. of ECE, Aristotle University of Thessaloniki, Greece
Abstract: The present work focuses on the design of periodic leaky-wave
antennas based on sinusoidally modulated reactance surfaces with
cylindrical symmetry. The surface impedance is realized using a
metasurface of square micro-patches which is loaded on a substrate.
Cylindrical surface waves are actuated through a coaxial probe and the
interaction with the periodic surface can – under certain conditions - result
Page 4 of 23
Thursday, May 23, 2013
12.20 – 12.40
Techniques Based on Artificial Neural Network Algorithms for the
Prediction of Path Loss in Urban Environments
Sotirios P. Sotiroudis1, Sotirios K. Goudos1, Katherine Siakavara1,
Konstantinos A. Gotsis1, and John N. Sahalos1,2
1
Radiocommunications Laboratory, Aristotle University of Thessaloniki,
Greece
2
University of Nicosia, Cyprus
Abstract: The accurate prediction of radio propagation in wireless
communications networks is becoming crucial. For a successful planning,
the prediction of path loss and the channel’s impulse response are
necessary. The capability of theoretically estimating the signal propagation
is particularly useful because in opposite case the corresponding
information could be obtained only by field measurements which are time
consuming and expensive. The existing prediction models can be classified
into statistical (or empirical) and site-specific (or deterministic) ones. Each
class of the models has advantages as well as drawbacks. It is noticed that
for the existing models, the accurate prediction of the ‘power profile’ of the
channel remains open. That is because; in several cases a great difference
between the theoretical and experimental results appears.
Our research team has been working on the synthesis of alternative
techniques based on Artificial Neural Network (ANN) algorithms for
accurate prediction of path loss. The propagation of radio waves in built-up
areas is strongly influenced by the size and the density of the buildings.
Urban areas are dominated by tall building blocks with high density and
non uniform distribution. Empirical prediction models use mean values for
the parameters of the manmade terrain (mainly the mean values of the
roads' widths and of the buildings' height). The aim of our work was to
synthesize ANN models which would be fed with detailed data of the
terrain of the area under coverage.
12.40 – 13.40
Lunch
13.40 – 15.40
WG2 presentations
Chair: Milos Mazanek
Mediterranean Palace Hotel
in radiation.
One main disadvantage of leaky-wave antennas is, in general, their large
size. In order to deal with this problem, attempts for minimization were
made through the maximization of the leakage factor. In this direction,
analytical design graphs were calculated and their combination with
substrate (reactance) capabilities investigation led to an optimum, in terms
of size, antenna design.
Based on the above minimization technique, an antenna at 14 GHz was
simulated, manufactured and measured. Highly satisfactory agreement
between simulation and experiment was observed, confirming the validity
of the proposed design methodology.
Page 5 of 23
Thursday, May 23, 2013
Practical considerations in design of wearable textile antennas
Branimir Ivšić, Davor Bonefačić, and Juraj Bartolić
University of Zagreb, Faculty of Electrical Engineering and Computing
Unska 3, HR-10000 Zagreb, Croatia
Abstract: Body-centric communication systems are the emerging
technology of the present time that attracts interest in many aspects of life,
ranging from military and rescue team communications on the terrain,
communications with medical implants used for telemedicine or drug
delivery, to the various tendencies in consumer electronic such as e.g.
wearable computers. Thus in the field of antennas the integration of the
antennas in clothes is being extensively researched, with the main goal to
achieve good radiation efficiency and large enough bandwidth, as well to
remain aesthetically acceptable and unobtrusive to the user. Good
candidates to meet these demands are planar antennas with textile
substrates.
Alongside influence of the human body on the antenna properties, another
layer of complexity in design of wearable antennas is the choice of proper
textile materials as dielectric substrates or, even more challenging, as a
conductive part of the antenna.
Application of conductive textile fabrics has a twofold effect: finite
conductivity of theconductive threads used for creating the fabric and the
effect of mixing conductive and nonconductive threads (recommended for
reducing the price and keeping functionality of clothes).
The ideal conductive textile material should resemble in its properties to
the conventional conductive material (such as e.g. copper), however it also
needs to retain the other properties of clothes, i.e. being comfortable to
wear, aesthetically appealing, washable, drapable and maintaining
affordable price.
In this paper we present a simple method for evaluating relative
permittivities of textile materials and propose embroidering the conductive
threads into conventional fabric as a simple method to create the
conductive textile. We also address the issue of applying the feeding on the
conductive textile by using metallic button as transition element.
14.00 – 14.20
Mediterranean Palace Hotel
13.40 – 14.00
Microfabrication technology for three dimensional antennas – u-helix
Paolo Nenzi, Volha Varlamava, Frank Silvio Marzano, Fabrizio Palma, and
Marco Balucani
Department of Information Engineering, Electronics and
Telecommunication (DIET), University of Roma – Sapienza
Abstract: The aggressive scaling of the CMOS technology and the
convergence of CMOS and MEMS technologies along the “More Than
Moore” axis of the International Technology Roadmap for Semiconductors,
paves the way to the realization of millimetre-waves front-end circuits with
integrated three- dimensional antennas. The realization of threedimensional antennas with tight tolerances is technology challenging and,
Page 6 of 23
Thursday, May 23, 2013
14.20 – 14.40
Performance of MISO Beamforming Systems based on Effective Radiation
Patterns
D. Zarbouti1, G. Tsoulos1, G. Athanasiadou1, C. Valagiannopoulos2
1
Depart. of Telecommunications Science and Technology, University of
Peloponnese, Tripolis, Greece
2
School of Electrical Engineering, Aalto University, Helsinki, Finland
Abstract: This work investigates the theoretical SIR gain of MISO
beamforming multicarrier systems when the antenna beamwidth and side
lobe level are considered in the system parameters via the concept of a
simple effective radiation pattern. The effective radiation pattern models
the result of the convolution of the power azimuth spectrum with the ideal
antenna pattern. In this context, it formulates and solves the relevant
optimisation problem for MISO beamforming multicarrier systems. Our
goal is to provide useful rules of thumb for selecting the appropriate
effective radiation pattern when information such as the number of
antenna elements and the Angular Spread (AS) of the environment power
azimuth profile are available. Results show that as the environment
becomes more and more dispersive the main lobe of the corresponding
effective radiation pattern becomes more and more wider destroying the
originally designed directivity of the antenna array.
In this line of thought, representative system design rules can be produced
for a variety of operational scenarios and antenna characteristics, in a
simple manner.
14.40 – 15.00
Extension to Characterization Model for GPS Antenna Performance in
Mobile Terminals
Janne Ilvonen, Kimmo Rasilainen, Risto Valkonen, Jari Holopainen, Joonas
Krogerus, and Ville Viikari
Aalto University School of Electrical Engineering, Department of Radio
Science and Engineering
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planar structures are preferred. Our group has developed a unique
technology enabling the realization and transfer of physically small
antennas at wafer scale level, with high yield and tight dimensional
tolerances. In this the technology, the conductor that defines the antenna is
patterned using lithography onto a porous silicon layer (for metal-silicon
adhension control) on a silicon wafer, with micron level accuracy on
position and dimensions (using semiconductor’s packaging equipment and
technologies).
Abstract: An improved MEG model to evaluate the performance of the GPS
antennas in mobile terminal in an open field environment and a new
parameter (IRR) to characterize their ability to reject the reflected waves
from the ground are introduced. It is shown that the new model can rank
the LHCP and RHCP cases properly, and that the new parameter (IRR) can
be used when designing GPS antennas with increased capability to reject
the multipath reflections from the ground. The statistical GPS multipath
environment model is improved by introducing the polarization losses due
to the ground reflections. It is also demonstrated how crucial it is to
Page 7 of 23
Thursday, May 23, 2013
estimate the GPS performance with at least two different antenna
orientations in order to avoid wrong conclusions.
Abstract: These studies are an extended work on previous research in the
field of the aperture coupled microstrip short backfire antennas carried out
during the last some years in TU-Varna. In the paper four aperture coupled
microstrip short backfire antenna arrays with linear polarization and
broadside radiation are designed and investigated by simulation: E-plane
and H-plane two-element antenna arrays with a common printed rim and
dielectric loaded backfire cavity, and E-plane and H-plane two-element
antenna arrays with a separately cavity – enclosed antenna elements and
printed rim. The obtained results of the studies are compared. The results
show that the directivity for arrays with a common printed rim is almost
the same as the directivity of the basic antenna element and therefore the
use of common rim is not suitable for creation an antenna arrays of
aperture coupled microstrip short backfire antennas with dielectric filled
cavity volume. The proposed new design of arrays with a separately cavity
– enclosed antenna elements by printed rim is a basis for creation of multielement high-gain broadside arrays and may find various applications in
modern communications.
15.20 – 16.10
Coffee Break
16.10 – 18.10
SWG3.1 presentations
Chair: Christophe Craye
16.10 – 16.30
Spectral Domain Approach for the Investigation of Leaky Wave Antennas
in Uniaxially Anisotropic Grounded Slab
Attieh Shahvarpour1, Christophe Caloz1, and A. Alvarez Melcon2
1
Ecole Polytechnique de Montreal, Polygrames Research Center, 2500,
Chemin Polytechnique, Canada
2
Universidad Politecnica de Cartagena, Campus Muralla del Mar, Cuartel
de Antigones, Cartagena E-30202, Spain
Mediterranean Palace Hotel
Studies of Two – Elements Aperture Coupled Microstrip Short Backfire
Antenna Arrays with Dielectric Filled Cavity Volume
G. T. Chervenkov and Sava V. Savov
University of Varna, Bulgaria
Abstract: In this work we develop a spectral domain technique for the
investigation of the behavior of surface and leaky modes in uniaxially
anisotropic grounded slabs, including material dispersive characteristics.
The work is motivated by the recent possibilities to manufacture practical
artificial substrates exhibiting interesting properties not found in natural
materials, such as negative permittivity and permeability [1],[2]. These
media, such as the mushroom type, are found to exhibit uniaxial
anisotropic behavior with medium dispersive characteristics of the Drude
Page 8 of 23
l
15.00 – 15.20
Thursday, May 23, 2013
and Lorentz type, for the permittivity and permeability parameters,
respectively. The resulting uniaxial anisotropic substrates are _rst
investigated under ideal non-dispersive conditions.
Then, a more realistic Drude/Lorentz medium dispersive behavior is
included in the model, to closely represent practical media, such as the
already mentioned mushroom type. The formulation is first derived by
extending the transmission line formalism of multilayered media Green's
functions to non-homogeneous substrates considering uniaxial anisotropy
[3]. This formulation is then used to obtain the dispersion relations of TMz
and TEz modes propagating in ideal uniaxial anisotropic substrates. Results
show that the characteristics of leaky modes propagating in the substrates
can be shaped by adjusting the parameters of the material anisotropy.
Moreover, it is shown that the inclusion of the more realistic Drude/Lorentz
medium dispersion, essentially preserves the same dispersive properties of
the modes.
Using this approach, material anisotropy can be adjusted to excite leaky
modes exhibiting wide band frequency behavior, with capabilities to scan
the whole space. On the other hand, leaky modes can also be shaped to
exhibit quasi-at dispersive behavior in a wide frequency band, therefore
presenting quasi-constant pointing angles needed in wide-band point to
point communication systems. The adjustment of anisotropy has been
previously proposed as a controlling parameter of circuit characteristics [4].
However, to the authors knowledge, this is the first time that this idea is
proposed to shape the behavior of leaky wave modes. To illustrate the
concept of the work performed, Fig. 1 shows a typical mushroom type
substrate, and its macroscopic model based on an e_ective anisotropic
medium. In Fig. 2 we present the dispersion characteristics obtained for
TMz modes in a typical mushroom substrate following the equivalent
model of Fig. 1. It can be observed that the leaky-mode bandwidth and
atness increases when the anisotropic parameter (εr /εz) is made larger.
Page 9 of 23
[1] N. G. Alexopoulos, “Integrated-circuit structures on anisotropic slab," IEEE Trans.
Microwave Theory Tech., vol. 38, pp. 847-881, October 1985.
[2] J. K. H. Wong, K. G. Balmain, and G. . V. Eleftheriades, “Fields in planar anisotropic
transmission-line metamaterials," IEEE Trans. Antennas Propagat., vol. 54, pp. 27422749, October 2004.
[3] G. W. Hansen, “Integral equation formulations for inhomogeneous anisotropic media
greens dyad withapplications to microstrip transmission line propagation and leakage,"
IEEE Trans. Microwave Theory Tech., vol. 43, pp. 1359{1363, June 1995.
[4] C. M. Krown, “Greens functions in the spectral domain for biaxial and uniaxial
anisotropic planar dielectric structures," IEEE Trans. Antennas Propagat., vol. 32, pp.
1273{1281, December 1984.
16.30 – 16.50
Mediterranean Palace Hotel
Thursday, May 23, 2013
Green’s functions for multilayered structures including conductive
interfaces and graphene sheets: development and novel numerical
evaluation
Ioannis D. Koufogiannis1, Athanasios G. Polimeridis2, Michael Mattes1, and
Juan R. Mosig1
1
Laboratoire d’Electromagnétisme et d’Acoustique, Ecole Polytechnique
Fédérale de Lausanne, 1015 Lausanne, Switzerland
2
Dept. of Electrical Engineering and Computer Science, Massachusetts
Institute of Technology, Cambridge MA02139, USA
Abstract: The development of Green’s functions (GF) for structures
including multiple conductive interfaces is a keypoint for the design and
analysis of future graphene-based microwave components and solar
antennas. Within the current contribution, spectral domain GFs’
representations are developed and a novel, efficient and error-bounded
Page 10 of 23
Thursday, May 23, 2013
method for the numerical evaluation of their spatial domain counterparts is
proposed. Finally, examples revealing the performance of the proposed
algorithms compared to reference methods are presented.a.
Memoization as a Simple Impedance Matrix Acceleration Technique
Albert A. Lysko
Meraka Institute of the Council for Science & Industrial Research (CSIR),
Pretoria, South Africa
Abstract: The impedance matrix computations frequently constitute a
noticeable portion of computations, especially for small to medium size
problems and for the codes not having an extensive support for hierarchical
description of geometry and providing for elimination of symmetries and
redundancies. It is possible to reduce the computational effort used for
filling in the impedance matrix by applying memorization. The computation
of complex sums is then done only once, stored, and, for every other
element, the result is simply retrieved from the cache (memo) and reused.
Under ideal circumstances, e.g. Toeplitz matrix, the technique can reduce
the number of computations from O(N^2) to O(N). Also, the technique is
especially efficient for in case of high accuracy requirements for impedance
matrix element. The method has been implemented in a method of
moments code. The tests indicated acceleration factor of an order of
magnitude.
17.10 – 17.30
Modeling of Electron Cloud Dynamics for Multipaction Analysis in
Microwave Devices
Apostolos L. Sounas, Eden Sorolla, Juan R. Mosig, and Michael Mattes
Laboratory of Electromagnetics and Acoustics (LEMA) Ecole Polytechnique
de Lausanne (EPFL), CH 1015 Lausanne, Switzerland
Mediterranean Palace Hotel
16.50 – 17.10
Abstract: A Multipactor effect is an RF discharge observed in microwave
cavities under vacuum or very low-pressure conditions, like in satellite
systems or particle accelerators. In brief, the underlined mechanism behind
the phenomenon is an electron avalanche which, under some resonant
conditions, is provoked due to a secondary emission mechanism on the
devices walls. As the time runs, a continuously increasing electron cloud is
evolving resulting in a breakdown. Serious problems may appear, like the
increase of the noise level, the growth of return losses or even the device
destruction. Therefore, multipaction prediction has attracted special
research interest since it constitutes a crusial issue in the design of payload
components, such as microwave filters, connectors and waveguides.
In this work, a computational model, able to take into account the electron
cloud evolution due to multipacting procedure, has been developed. A
realistic secondary emission model has been implemented taking into
account the statistical behavior of the phenomenon. Time domain
simulations reveal interesting results about the electron cloud distribution
inside microwave cavities due to the multipacting process.
Page 11 of 23
Thursday, May 23, 2013
Enhancing and expanding the capabilities of FEBI, a hybrid
electromagnetic solver
C.A. Liontas
Fraunhofer Institute for High Frequency Physics and Radar Techniques FHR,
Fraunhofer Str. 20, 53343 Wachtberg, Germany
Abstract: A The experimental research EM solver used at the Antennas and
Electromagnetic Modeling (AEM) Department of the Fraunhofer Institute
for High Frequency Physics and Radar Techniques (FHR) is FEBI (from Finite
Elements – Boundary Integral). According to its name, it uses a
hybridization of the Finite Element Method (FEM) with the Boundary
Integral Method (BIM), the latter being discretized with the Method of
Moments (MoM) and accelerated with the Multilevel Fast Multipole
Method (MLFMM). It was originally developed by T. Eibert in the mid-90s
and its development continues to this day, both at FHR and at the Technical
University of Munich. This contribution will describe the targets and
methods of the author in improving the performance and expanding the
simulation capabilities of FEBI.
In the overall simulation cost (CPU time and RAM requirements) of FEBI,
the main bottleneck consists in modeling dielectric objects with the FE
Method. The hybridization of FEM with BIM provides versatility in modeling
arbitrary (possibly inhomogeneous and anisotropic) materials, but it results
in a linear system matrix with bad convergence properties (sparse-FEM
with dense-BIM). The simulation cost can be drastically reduced in case of
homogeneous dielectrics. In short-term, one can model homogeneous
dielectric volumes with thin FEM-layers enclosing fictitious BIM-cavities.
This layers act as couplers between the inside and the outside BIM
problems. The long-term solution is to omit FEM for homogeneous
dielectrics altogether, and to use a pure surface integral equation (SIE)
formulation like PMCHWT or JMCFIE. In doing so, extra care must be
exercised in modeling multiple junctions of different materials.
In the direction of expanding the simulation capabilities of FEBI, we have
turned our attention in modeling new excitations. The currently supported
excitations are plane waves (scattering problems) and delta-gap voltages
(radiation problems). We have implemented a new scattering excitation:
the field of an elementary electric or magnetic dipole. The simulation
results show good agreement with expected results. Furthermore, we have
implemented a waveguide-port excitation for exciting structures with the
TE10 mode of a rectangular waveguide. In this way one can also calculate
the S11 parameter of a structure. However, hitherto results show some
moderate discrepancies in amplitude compared to analytical results. An
explanation for this might be the point-collocation technique in which the
TE10 mode pattern is impressed on the port mesh. Better alternatives
include (a) expanding the TE10 field in RWG basis functions, and (b) solving
numerically for the eigenmodes of the port (2-dimensional FEM problem).
The (b) option paves the way for implementing waveguide ports of
arbitrary cross-section and will be implemented in the future.
Mediterranean Palace Hotel
17.30 – 17.50
Page 12 of 23
Thursday, May 23, 2013
Bandwidth limitations regarding cloaking from a total cross-section
perspective
Christophe Craeye and Arnab Bhattacharya
Université catholique de Louvain, ICTEAM Institute, Place du Levant 3, 1348
Louvain-la-Neuve, Belgium
Abstract: Cloaking is an interesting phenomenon since it would have been
considered utopic only a decade ago. However, it is often considered as a
curiosity since it would be “practically unfeasible” or theoretically possible
over an infinitely narrow bandwidth. Yet a few demonstrators have been
realized and the experimental verification of this phenomenon may move
faster than that of the superlens. So far, the main limitations regarding
cloaking concern: (i) dual-pol. operation over 3D objects, (ii) highly
resonant inclusions which may lead to important losses by absorption and
(iii) limited bandwidth.
It is commonly accepted that bandwidth limitations may stem from
causality limits. In this paper, we will consider that object to be cloaked
should be concealed from incident fields and may hence be enclosed in a
perfectly conducting shield. Hence, light needs to channeled around the
object and may need more time to travel around the new path, as
compared to straight propagation in free space. This has led the authors to
a simple rule of thumb regarding bandwidth, based on a wave-packet
argument. A modulated wave packet has a bandwidth inversely
proportional to the width of its envelope. In view of causality limits, the
wave packet arrives late on the other side of the object. That delay leads to
important distortion when it is non-negligible compared to the width of the
envelope. If the ratio between the latter two quantities is 1/Q (Q indicates
a high fidelity pulse transmission), then –for relatively narrowband
operation- the maximum bandwidth become approximately: B ~ / R 1/Q
where l is the wavelength at central frequency and R is the extra path
followed by light around the object [1]. Using a set of optimistic
assumptions, the authors showed that a quality factor between 3 and 9
could lead to what is generally considered as “good cloaking” in the
literature.
The authors verified, using a set of optimistic assumptions, that the quality
of fields (i.e. minimum perturbation) is good for a quality factor between 3
and 9. It is also useful to relate the cloaking bandwidth to the total
scattering cross-section of the combined object and cloak. This will be
presented here based on a few assumptions regarding the fields on the
outer (cylindrical) surface of the structure: while magnitude is the same as
in the perfect cloak case, phase is constrained such that the maximum
group velocity corresponds to the velocity of light in free space. Assuming
perfect cloaking at a given frequency, the obtained bandwidth is
proportional to /a (a is the radius of the cylinder) and to the square-root
of the acceptable total scattering cross-section.
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17.50 – 18.10
[1] C. Craeye and A. Bhattacharya, “Rule of Thumb for Cloaking Bandwidth
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Thursday, May 23, 2013
18.10 – 18.30
18.50 – 22.20
Extension to Characterization Model for GPS Antenna Performance in
Mobile Terminals
Janne Ilvonen, Kimmo Rasilainen, Risto Valkonen, Jari Holopainen, Joonas
Krogerus, Ville Viikari
Aalto University School of Electrical Engineering, Department of Radio
Science and Engineering, Finland
Abstract: An improved MEG model to evaluate the performance of the GPS
antennas in mobile terminal in an open field environment and a new
parameter (IRR) to characterize their ability to reject the reflected waves
from the ground are introduced. It is shown that the new model can rank
the LHCP and RHCP cases properly, and that the new parameter (IRR) can
be used when designing GPS antennas with increased capability to reject
the multipath reflections from the ground. The statistical GPS multipath
environment model is improved by introducing the polarization losses due
to the ground reflections. It is also demonstrated how crucial it is to
estimate the GPS performance with at least two different antenna
orientations in order to avoid wrong conclusions
Social Dinner
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Based on a Wave-Packet Argument,” IEEE Trans. Antennas Propagat, Vol.
60, pp. 3516 – 3520, July 2012.
Science
Center &
Technology
Museum
“NOESIS”
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ESR Forum – Poster presentations
Omni-directional CP Antenna Techniques
Adam Narbudowicz and Max Amman
Antenna and High Frequency Research Centre (AHFR), Dublin Institute of
Technology, Dublin 8 – Ireland
Abstract: We propose an omnidirectional circularly-polarized planar
antenna, which is able to electronically rotate its dipole-like CP radiation
pattern along an axis. The antenna - developed at Dublin Institute of
Technology is fully realized using planar multilayer PCB technology, is easy
to manufacture and cost efficient. The rotation of the dipole-like radiation
pattern allows reception (or transmission) of signals from practically all
angles around the sphere. The method also enables continuous pattern
steering without semiconductor or MEMS components and allows the use
of more than one radiation pattern simultaneously (i.e. through power
divider), potentially providing coverage of any spherical angle.
The measurement of this antenna poses a significant challenge, as the
supporting structure and feed network may corrupt the results of the
steerable omnidirectional beam. Also, to properly validate the antenna
concept, a 3D dual polarized radiation pattern is required. Expertise and
equipment available at RWTH Aachen University allowed us to confirm our
simulations and prove functionality of the proposed antenna.
Observable Reactive Energies of Radiating System and the Measurable
Q-factor
Pavel Hazdra and Miloslav Capek
Czech Technical University in Prague, Faculty of Electrical Engineering,
Department of Electromagnetic Field, Czech Republic
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All day
Abstract: This contribution shows how to derive the expressions for
electromagnetic energies simply from the complex Poynting theorem
(CPT). These energies are the same as defined by prof. Vandenbosch in his
paper from 2010. The study within the STSM at KU Leuven (prof.
Vandenbosch) revealed that that the total energy is unphysically negative
for some special current distributions. The proposed remedy lies in
employing the definition for Q that is based on frequency change of input
impedance and this is the only Q which is actually measurable and thus
physical.
Implantable Antennas for Medical Telemetry: Design and Link Budget
Issues
Asimina Kiourti1, Jorge R. Costa2, Carlos A. Fernandes2, and Konstantina S.
Nikita1
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1
Abstract: Implantable Medical Devices (IMDs) are recently used in several
diagnostic and therapeutic medical applications (e.g., heart rate
regulation, pain control, drug delivery, and neurological tremor treatment
etc). Bidirectional telemetry between the IMD and exterior
monitoring/control equipment is most commonly performed wirelessly, by
means of an integrated implantable antenna. Numerical and experimental
investigations of implantable antennas have proven to be highly
intriguing, and are currently attracting significant scientific interest.
In this study, we address design and link budget issues of implantable
antennas for integration into IMDs and medical telemetry in the Medical
Implant Communications Service (MICS) band (402–405 MHz). Novel liquid
and gel phantoms are initially formulated for muscle–tissue emulation in
the MICS band (εr = 57, σ = 0.8 S/m). Formulation of tissue–emulating
materials is important for in–vitro characterization of implantable
antennas. Furthermore, solidification of liquid phantoms is commonly
solicited for simplifying measurements and better emulating the intended
implantation scenario. Dielectric properties of the phantoms are
experimentally measured with the help of a low–cost, yet reliable,
technique which has been proposed by the authors previously .
Switches and phase shifters characterization for automotive switchable
antennas
Gonzalo Expósito-Domínguez1, José -Manuel Fernández-González1,
Manuel Sierra-Castañer1, and Marta Martínez-Vázquez2
1
Radiation Group, SSR Dept. Technical University of Madrid. 28040, Spain
2
Department of Antennas and EM Modelling, IMST GmbH. Kamp-Lintfort
47475, Germany
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School of Electrical and Computer Engineering, National Technical
University of Athens
2
Instituto de Telecomunicações, Instituto Superior Técnico, Portugal
Abstract: The main objective of this STSM was to characterize high
frequency switches and phase shifters for electronically steerable antenna
systems. At 24 GHz, free space losses are critical and the power
transmitted is limited, therefore the insertions loss in the distribution
feeding networks must be as small as possible maintaining the symmetry
regarding insertion loss for the different states. By combining different
circuitry topologies and components two states phase shifters and SPDT
switches are designed.
On the Design of a Planar Phased Array Radar Antenna Architecture for
Space Debris Situational Awareness
Javier García-Gasco Trujillo1, and Stéphane Halté2
1
Radiation Group, Systems and Radiocommunications
1
Department. Technical University of Madrid, Madrid, Spain
2
European Space Agency/European Space Operations Center Ground
Systems Engineering Division, Darmstadt, Germany
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Unit Cell for Frequency-Tunable Beamscanning Reflectarrays
Daniel Rodrigo1, Louis Jofre1, and Juliene Perruisseau-Carrier2
1
UPC, Barcelona, Spain
2
EPFL, Lausanne Switzerland
Abstract: We present the first implementation of a reflectarray (RA) cell
combining reflection phase tunability with frequency reconfigurability.
Although frequency reconfiguration can not increase the RA instantaneous
bandwidth, it will be useful for narrow/moderate bandwidth applications
whose operating band changes over a much wider frequency range.
- Frequency-hopping radar and communications
- Remote sensing and imaging
- Cognitive radios
- Ka-band satellite communications covering Tx/Rx bands.
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Abstract: A The Space Situational Awareness (SSA) program from the
European Space Agency (ESA) protects Europe’s citizens and their satellitebased services by detecting space hazards. ESA Ground Systems (GS)
division is currently designing a phased array radar composed of
thousands of radiating elements for future stages of the SSA program. The
radar shall guarantee the detection of most of Low Earth Orbit (LEO)
space debris, providing a map of space junk. While range accuracy is
mainly dictated by the radar waveform, the detection and tracking of
small objects in LEO regimes is highly dependent on the angular accuracy
achieved by the smart phased array antenna, demonstrating the
important of the performance of this architecture. To predict the
performance of the whole system, ESA has developed a completed SSA
radar simulator tool. This Matlab simulator is capable of analyzing all
related mechanisms involved in radar operation, from the external
environment modeling to the data processing, extracting plots and tracks.
It supports, among others, several radar architectures (monostatic, close
monostatic and bistatic), different kind of waveforms (pulsed and
continuous wave), various array topologies (radiofrequency and digital
beamforming), two tracking methodologies (track while scan and active
tracking), and distinct radar processes (coherent and non-coherent).
Diffracted Image Restoration: A Machine Learning Approach
Vlastimil Koudelka1, Carlos del Río Bocıo2, and Zbyněk Raıda1
1
Department of Radio Electronics Brno University of Technology
Brno, Czech Republic
2
Antenna research group, Public University of Navarra, Pamplona, Spain
Abstract: Image restoration issues are closely connected with imaging
systems, where an image resolution is limited by diffraction phenomenon.
The presented work is motivated by the super acuity of the Human vision,
where the restoration step is implemented by some kind of a parallel
processor unit – neural network. The de-convolution process is formulated
as a machine learning problem and the inverse operator is interpreted as
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a connectionist model.
Abstract: A The effort to integrate one or more antennas (e.g. for the
realization of a MIMO antenna system in a small terminal) is a challenge
that is barely to cope. Due to the spatial limited structure some antenna
performance measures, such as the Q-factor or the efficiency, are affected
by the integration impairments of the small terminal. The TCM (Theory of
Characteristic Modes) provides one possible approach in order to
understand the impact of the small terminal and the effects on the overall
radiation. The characterization of a given 3-port MIMO antenna system is
based on the eigenvalue analysis with respect to the TCM. The selective
excitation of three desired modes is realized by 3 sets of non-resonant
inductive coupling elements (ICEs). The modal Q-factor calculations are
based on the theory of Foster, Vandenbosch and Harrington and have
been applied to the 3-port antenna system in order to understand the
natural radiation mechanism. A comparison of the Q-factors between a
simple rectangular plate and the given 3-port antenna system has shown
low deviation. The modal analysis of the total radiation Q-factor for the
given 3-port MIMO antenna system shows a high purity of the mode
excitation. Some optimizations of non-resonant coupling structures have
shown that the Q-factor of each port excitation could be decreased in
comparison to the given antenna system.
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Discussion and Evaluation of Modal and Total Radiation Q-Factors for
MIMO Antennas Based on the Theory of Characteristic Modes
E. Safin1, R. Martens1, M. Capek2, J. Eichler2, P. Hazdra2, D. Manteuffel1,
and M. Mazanek2
1
Chair of Wireless Communications, Institute of Electrical and Information
Engineering, Christian - Albrechts - University of Kiel, Kaiserstrasse 2,
24143 Kiel, Germany
2
Czech Technical University in Prague, Faculty of Electrical Engineering,
Department of Electromagnetic Field, Technicka 2, 166 27, Prague, Czech
Republic
Specific Absorption Rate (SAR) Evaluation of Textile Antennas
Ping Jack Soh1, Guy A. E. Vandenbosch1, Andre van den Bosch2, Marta
Martinez-Vazquez2, and Dominique M. M.-P. Schreurs1
1
ESAT-TELEMIC Research Div., KU Leuven, Kasteelpark Arenberg 10, 3001
Leuven, Belgium.
2
IMST GmbH, Carl-Friedrich-Gauss-Str. 2-4-4, 47475 Kamp-Lintfort,
Germany.
Abstract: On-body placement of textile antennas is expected to incur
degradation in terms of bandwidth and reflection performance due to
power absorption and body coupling. Several prototypes of broadband
and dual-band textile antennas have been recently proposed and
developed in KU Leuven. Besides proper topology and feeding selection,
antennas must be co-simulated with a body-emulating structure during
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design stage at locations where the antennas are intended for operation.
A detailed investigation of the radiation performance and efficiency
degradation operated on-body relative to free space have been
completed. The remaining issue is to ensure conformance to safety
regulations when the antennas are placed near a human user, prior to
their implementation on clothing. This is achieved by verifying the
antennas' Specific Absorption Rate (SAR), which defines the maximum
allowable RF energy absorption into the human user's tissue. This
investigation is aimed to further gather exact SAR levels through the use
of a certified facility and standard-defined procedures available at IMST.
Twenty-two prototypes of dual- and wideband textile antennas designed
and fabricated from various materials were measured using a certified
DASY 4 SAR measurement system available at IMST. Two frequency points
were chosen for measurements, at 2.4 GHz and 5.2 GHz. A repeatability
test conducted prior to the start of the measurement campaign indicated
a maximum uncertainty of 10.5%, although most of them are lower.
Variation of this uncertainty is also dependent on antenna topology and
frequency. All measurements conducted on the planar inverted-F antenna
(PIFA) indicated a maximum of 0.6 W/kg averaged over 10g of tissue,
which is far less than the European regulated limit of 2 W/kg.
MUSIC-based Breast Cancer Detection: Experimental Results and
Analytic Comparison
Giuseppe Ruvio
Trinity College Dublin, Ireland and Seconda Università di Napoli
Abstract: From the promising results obtained on preliminary simplified
numerical breast models, the investigation on the performance of
detection algorithms based on Multiple Signal Classification (MUSIC) was
carried out on more realistic scenarios. In particular, measurements were
made on an oil-in-gelatin tissue-mimicking breast phantom with planar
monopole antennas scanning it across 36 different positions. The
detection of a 6-mm radius tumor was successfully performed and the
performance of an Interferometric MUSIC approach was proven to be
higher than other non-coherent linear algorithms which are normally
proposed in the literature (i.e. Migration and standard MUSIC).
Alternatively, the detection system was also numerically evaluated on the
basis of breast voxel models which were generated from real Magnetic
Resonance Imaging MRI scans. Also in this case, the Interferometric
MUSIC technique enabled successful tumor detection.
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09.00 – 09.40
SWG3.2 presentations
Chair: Christophe Craye
09.00 – 09.20
Speed-up for phaseless antenna measurement based on Leith-Upatnieks
holography
Jaime Laviada and Fernando Las-Heras
Signal theory and Communications Group. Dept. Electrical Engineering.
Univ. of Oviedo, Edif. Polivalente, Mod. 8, Campus Universitario. E-33203.
Gijón (Asturias), Spain
Abstract: Phaseless acquisition plays a key role at high frequencies or in
environments where the thermal stability is poor. One of the conventional
handicaps of these techniques is that they involve a denser sampling. In
this work, the phaseless acquisition based on Leith-Upatnieks holography
is implemented with a synthetic reference field as proposed in. This
scheme enables us to control the phase of the reference wave which is
used to introduce a phase reduction factor as calculated previously.
Moreover, this phase factor is introduced in a parametric domain resulting
in a non-uniform sampling.
As a consequence, the acquired field has a smaller bandwidth and,
therefore, the sampling step, which is formulated in the parametric
domain, can be increased. Once the reduced field has been acquired,
optimal sampling interpolation is used together with the inverse phase
reduction factor to retrieve the amplitude and phase of the real field.
The technique is illustrated with several practical examples which reveal
that the reduction in the number of acquisition points involves a negligible
error in the retrieved field.
09.20 – 09.40
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Friday, May 24, 2013
Antenna Measurement Setup for a 77GHz Patch Antenna With
Supressed Surface Wave
Mohammad Hossein Nemati1, Mehmet Kaynak2, and İbrahim Tekin1
1
Electronics Engineering, Sabancı University, İstanbul, Turkey
2
IHP GmbH, Frankkfurt (Oder), Germany
Abstract: A patch antenna with supressed surface wave has been
designed and will be measured at Sabanci University. Supressing the
surface wave improves both antenna gain and radiation pattern. The
surface wave suppression is done by filtering mechanism of
Electromagnetic Bandgap structure (EBG). Array of patch antenna with
improved performance can be used for automotive radar purposes at
77GHz. Moreover, a measurement setup has been built to measure the
gain and far-field radiation pattern of millimiter-wave antenna in both E
and H-planes.
Millimeter wave technology brings about many promising feature such as
possibility of high speed communication, less interference, etc. However,
conducting experiments at this frequency band requires high precision
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Friday, May 24, 2013
09.40 – 10.10
Coffee Break
10.10 – 11.40
WG4 presentations
Chair: Juan R. Mosig
10.10 – 10.20
Finding NEMO-land
Ioan Lager1 and Juan R. Mosig2
1
Delft University of Technology, the Netherlands
2
EPFL, Lausanne, Switzerland
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devices and also high level of dexterity. Our antenna measurement setup
at Sabanci University seeks to fulfill these necessities and make reliable
measurement possible. To do so, our measurement setup follows all the
standard procedure in antenna measurement. This setup enables
reflection coefficient, gain and far-field radiation pattern measurement.
Our antenna under the test (AUT) is a simple inset-fed patch antenna
surrounded by EBG structure. A copy of the antenna has been realized by
printed board technology available at IHP, Germany. To connect the
antenna to signal source, an GSG RF probe is used. Fine adjustment is
obtained by a micro positioner. On the other side is the collecting arm that
receives the field radiated by antenna by mean of standard gain horn
antenna. This arm solely rotates at elevation. Using two different GSG
probe, AUT can be rotated 90 degree with respect to rotation plane at
elevation so we can switch from E to H plane measurement and vice versa.
Besides, the standard horn can be rotated in 0,90 degree with respect to
collecting arm and make it possible to determine the co- and crosspolarization at E and H plane.
Abstract: A Introducing NEMO (http://www.e-nemo.nl/en/) the
Netherlands’ largest science center with 500,000 visitors every year and
discussing the possibility of having a COST IC1102 VISTA Exhibit on it,
geared to kids and the laymen.
10.20 – 10.30
An appraisal of the “Girl’s day” at IMST.
Marta Martinez
IMST, Germany
10.30 – 10.50
A Massive on Line Open Course (MOOC) on Antennas
Miguel Ferrando Bataller
ITEAM Universitat Politècnica de Valencia, Spain
Abstract: A The presentation will propose the creation of a European
multimedia course on Antennas at the introductory level.
The course would have the following characteristics
MASSIVE: Aimed at students worldwide wishing to enter the world of
antennas
OPEN: Fully open, distributed on the internet ONLINE: Using multimedia
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Friday, May 24, 2013
10.50 – 11.10
Parasitic antenna arrays for greener wireless communications
Constantinos B. Papadias
Athens Information Technology, Paiania 19002, Athens, Greece
Abstract: A The field of parasitic antenna arrays is an old one but it has
recently gained renewed attention due to the ability to control these
arrays via digital circuits. Moving on a slower but parallel track with the
advent of MIMO systems, parasitic arrays can be now designed that offer
basic diversity, beamforming and spatial multiplexing capabilities. In this
talk we will review some example techniques where these types of
processing can be attained. We will then focus on the practical
implications of this emerging technology with an eye towards more
energy and spectrally efficient applications, in the direction of greener
future wireless networks.
11.10 – 11.40
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technologies, specifically Polimedia technology developed at the
Universitat Politecnica de Valencia
The courses MOOC's are having a strong impact on global initiatives such
as edX, Coursera, Udacity.
UPV recently participated in the initiative MiriadaX. More than 70,000
students have enrolled in various courses in Engineering. The proponent
has coordinated a course with more than 2500 enrolled.
At this time an opportunity arises to create a European course on
Antennas, with the participation of teachers participating in the VISTA
COST program. Already have successful experiences with different
modules undertaken as part of the European School of Antennas, in
collaboration with IEEE APS.
UPV will provide the necessary resources for course preparation.
Radioastronomy and the Antikythera Mechanism: An ancient Greek
astronomical computer
John H. Seiradakis
Aristotle University, Department of Physics
Laboratory of Astronomy, GR-541 24 Thessaloniki, Greece
Abstract: A The Antikythera Mechanism was a portable (laptop-size),
geared mechanism, built ca. 150–100 BCE, which calculated and
displayed, with high precision, the movement of the Sun and the Moon on
the sky and the phase of the Moon for a given epoch. It could also predict
eclipses and calculate the dates of the Olympic Games. Its 30, precisely
cut, gears were driven by a manifold, with which the user could select,
with the help of a pointer, any particular epoch (at the front dial). While
doing so, several pointers were synchronously driven by the gears, to show
the above mentioned celestial phenomena on several accurately marked
annuli. It contained an extensive user’s manual. The exact function of the
gears has finally been decoded and a large portion of the manual (~3000
letters) has been read after 2000 years using the latest techniques in X-ray
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computed tomography and reflectance imaging. Nowadays, astronomers
using imaging tools of modern astronomy and astrometry build state-ofthe art radio telescopes pursuing their vision for exciting scientific
discoveries of the Cosmos.
11.40 – 12.00
Wrap up – Closing
12.30 – 15.30
Tour around the city
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Palace Hotel
Friday, May 24, 2013
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