STSM summaries

Completed and Agreed Short-term Scientific Missions

 

2009/2010

 

 

11. Elena Pucci, Antenna Group, Department of Signals and Systems, Chalmers University of Technology, Gothenburg, Sweden to University Carlos III of Madrid, Spain, June 2010

The purpose of this STSM is to continue the collaboration between Antenna Group at Chalmers University and Prof. Eva Rajo Iglesias, University Carlos III, on a project about a new waveguide technology, called gap waveguide. The gap waveguide is a result of research on soft and hard surfaces, first done at Politechnical University of Valencia and Carlos III of Madrid and then developed at Chalmers University since August 2008. The new technology is based on the conventional parallel plate waveguide concept plus the use of an artificial magnetic conductor (AMC) in order to kill higher order modes, allowing the only quasi-TEM mode to propagate in the gap between the lower and upper metal plates. Numerical and experimental validations showed that the new gap waveguide is very low loss and suitable for applications up to THz and integration of active components since there is no need of any dielectric and any metal contacts between the two plates. The artificial magnetic conductor chosen as first demonstrator is a textured surface, known as bed of nails, which appears as an ideal perfect magnetic conductor (PMC) under certain conditions. During this STSM we plan to study the possibility of using other different artificial surfaces with the experience of Prof. Eva Rajo on analysing such surfaces and to investigate the effects on the performance of the gap waveguide in terms of bandwidth, losses and for different operation frequency ranges. Besides, the recently developed topology named as groove-type gap waveguide will be explored with the purpose of developing arrays of waveguides. In summary, these are the tasks proposed for the mission: (i) Identification of artificial surfaces different from the bed of nails (printed type EBGs, springs, etc) that could be used to design a gap waveguide. (ii) Numerical study of the most interesting surfaces in terms of waveguide bandwidth, losses, field confinement, etc. (iii) To define which surfaces are more appropriate for the different frequency ranges and for the different gap waveguide topologies (ridge, groove…). Designing, manufacturing and measuring of a prototype in planar technology for low frequency. (iv) Finally, we propose to perform initial studies on the viability of designing arrays of waveguides with groove-type topology, with emphasis on the study of the coupling between neighbouring elements. This study will go on after the STSM as long term collaboration between Chalmers and Carlos III universities. The results of such STSM are expected to deserve publication in international conferences or even journal. The writing of the manuscript will be organized during the STSM.

 

10. Giuseppe Ruvio, Dublin Institute of Technology, Dublin, Republic of Ireland to University of Naples, Italy, February 2010 – May 2010

UWB technology has enabled advanced microwave-based imaging techniques, which are non-invasive, non-ionizing and low-cost. This opportunity appears particularly suitable for breast cancer detection as documented in recent literature and successful clinical tests. The DIT has leading contributions in several high quality, peer-reviewed, journal papers and in many conference proceedings. As a consequence of the novelty of this research topic, a characterisation of the radio-frequency requirements for UWB-based imaging applications is still in progress and requires the collaboration of signal processing expertise and a solid simulation platform for the correct evaluation of the prototypes. These experimental infrastructures have been found at the research group led by Prof. Pierri in Naples, Italy. Pulse/bandwidth/field penetration optimised antennas will be a critical enabler for the realisation of cost effective sub-centimetre image resolution using a UWB impulse method. The RF aspects of this project will quantify the merits of integrating three advanced antenna solutions with the objective of enhancing emerging applications and improving resolution. The characterisation of the antenna through the signal processing requirements and the imaging system validation on high-performance software and body phantoms will build a significant reference in specific literature and likely lead to technology transfer opportunities.

 

9. Jan Puskely, Technical University of Brno, Czech Republic to University of Calabria, Italy, May 2010

The proposed STSM will focus on the research cooperation in the area of antenna near-field measurement techniques. Emphasis will be put to phaseless measurement techniques, especially. The so-far work of the applicant was devoted to phaseless measurements on two planar surfaces, on the reconstruction of the phase information by the minimization of properly composed functional, and on the reduction of computational demands by the application of image processing techniques. Within the frame of the STSM, the so-far development is going to be confronted with other techniques developed by the host institution (exploiting curved sensing planes, using a single plane and two sensors, etc.). Second, the experimental facilities of the host institution will be used for the experimental verification of so-far developed methods. Third, the methods will be mutually compared. Finally, a paper on worked out comparisons will be published.

 

8. Tomislav Debogovic, University of Zagreb, Croatia to CTTC, Barcelona, Spain, March 2010 – April 2010

In order to meet the ever growing need for new capabilities and enhanced performance in communication or radar systems, there has been significant interest in so called ‘smart’ surfaces, such as frequency selective surfaces (FSS), absorbing surfaces, or surface which can locally control the reflection or transmission phase of an incoming wave (reflect/transmit array). At the same time, reconfigurability has become a key need in microwave system, for frequency/polarization/pattern reconfiguration, in-flight satellite mission update, etc. In this context, there is evident interest in developing new smart reconfigurable surfaces, allowing the dynamic reconfiguration of parameters such as the amplitude of reflected or transmitted wave, their polarization, their frequency response, and so on. The purpose of this mission is to design (a) novel reconfigurable cell(s) for such surface. During the time before the STSM, potential candidates for the cell and its corresponding capabilities and applications will be investigated by Tomislav Debogovic under the supervision of Prof. Juraj Bartolic and Dr. Julien Perruisseau-Carrier. Then, in the first part of the visit the most suitable candidate will be chosen and designed using the available EM simulation tools. After that period and according to the obtained results, the cell or array of cells will be fabricated using the available technology. Measurements will be performed in both institutions using the available equipment. Dr. Perruisseau-Carrier (CTTC) is very experienced in the design of controllable reflecting surfaces such as reflect-arrays. The group from University of Zagreb has experience in reconfigurable antennas, reconfigurable phase shifters and generally in antenna and microwave measurements. In both institutions there is also considerable experience in metamaterials which can be very convenient for the design of the reconfigurable surfaces.

 

7. Alexander Vasylchenko, KU Leuven, Belgium to QMU London, United Kingdom, November 2009 – March 2010

Presently, a planar UWB antenna was designed and fabricated at Katholieke Universiteit Leuven (KUL). Its initial performance estimation was carried out in frequency domain at KUL. Additional measurements in time domain proposed by Queen Mary University of London (QMUL) would complete evaluation of the antenna performance. In the second phase of my short-term mission, a waveguide to microstrip feeding transition working at 60 GHz will be designed. The transition should be based on the PCB build-up of the existing 60 GHz antenna. It will also be adapted for use in the existing measurement setup at QMUL. Finally, a calibration TRL standard will be designed and produced for calibration of the waveguide to microstrip transition for radiation pattern and return loss measurements.

 

6. Mikko Kyrö, TKK, Finland to CNRS-LEAT, Nice, France, 23 November 2009 –3 December 2009

This mission is a part of the antenna evaluation work carried out by the Department of Radio Science and Engineering of TKK (RL) and the LEAT of University of Nice. The aim of the mission is to built a 3D radiation pattern measurement system for on-wafer 60 GHz antennas and measure several antennas using the system. With this system the radiation patterns of on-chip mm-wave antenna systems can be measured directly on the wafer. The advantages of on-wafer measurement are that it is faster, less expensive and requires less effort than measurement in anechoic chamber (no need to cut the wafer, to solder connectors, etc). Moreover, according to our knowledge, only few equivalent antenna-measurement systems exist within the world. A conference or a journal paper as well as at least one TD are written based on the joint work carried out about the results this mission.

 

5. Martin Stumpf, TU Brno, Czech Republic to TU Delft, the Netherlands, 2 November 2009 – 18 December 2009

The scheduled mission is aimed at the analytical solution of certain types of a 3D slot antenna consisting of a ground plane and a dielectric layer. The 2D equivalent with an infinitely narrow slot has been already solved via Cagniard-de Hoop technique, in the frame of the previous STSM. The effect of the finiteness of a slot width and a potential application of the extended Cagniard-de Hoop technique employing the Schouten-Van der Pol theorem shall be discussed. After these preliminary discussions, the selected configurations shall be analyzed. Another scheduled topic is a time-domain analysis of spatially periodic structures. Based on the Floquet theorem, some kind of the discrete wave slowness field representation could be combined with the unilateral Laplace transformation leading to the new formulation of the problem. The attention will be mainly focused on the plane wave incidence on a periodic structure.

 

4. Caner Güçlü, METU, Turkey to CTTC, Barcelona, Spain, 26 October 2009 – 7 November 2009

A In this study we aim to design a novel reconfigurable dual band reflectarray cell. Reconfigurability will be provided by RF-MEMS switches. In the literature there are a few examples of dual band reflectarrays, which are not reconfigurable. Before the STSM visit, possible dual band reflectarray (RA) configurations will be investigated by Caner Güçlü under the guidance of Ozlem Aydın Civi from METU and in contact with Julien Perruisseau-Carrier from CTTC. During the STSM, one RA cell topology will be chosen from these several options. Then dual-band RA cell with RF-MEMS switches will be designed using available EM modelling tools under the guidance of Dr. Perruisseau. The RF-MEMS switch designed by METU group will be used in the reconfigurable RA cell. After the STSM visit, the designed RA will be produced and measured in the facilities of METU.

 

3. Francesco Merli, LEMA-ELB, EPFL, Switzerland to U Rennes, France, 19 September 2009 – 4 October 2009

Recently, the host and visitor institution research teams started the joint research about the analytical analysis of the insulation effect in a simplified body model. The preliminary results of this work were presented at EuCAP 2009 conference (Berlin, 2009). It has been shown that a judicious choice of the biocompatible material properties (thickness and dielectric constant) can reduce the total lost power and thus, increase the antenna’s efficiency. The aim of this scientific mission is to progress in the joint research of the study of the biocompatible insulation material effects on implanted antennas for telemetry applications.

 

2. Pablo Padilla de la Torre, UP Madrid, Spain to TKK, Finland, 11 August 2009 – 5 September 2009

The main purpose of this short stay at Radiolab of the Helsinki University of Technology (TKK) is to deeply study the systems already working in this laboratory, as they have wide experience in hundred on GHz system design and measurement. In particular, the Radiation Group has decided to extend the frequency range of their facilities, with the advices and recommendations of people working at Radiolab, at TKK. In this way, some actions are going to be taken, and this short stay is included in these actions. In particular, the guest is going to study the measurement systems available at Radiolab, and the possible adaptation of their systems to 90 GHz and 300 GHz measuring systems for the Radiation Group facilities. In this way, the guest is going to carry out some work together with Radiolab, in order to generate synergies between our two institutions (TKK and UPM). The guest is also going to study design possibilities of antennas at these frequencies, taking Radiolab wide experience as a starting point, in order to extend in frequency the design capabilities of the Radiation Group.

 

1. Alfonso Muñoz Acevedo, UP Madrid, Spain to TKK, Finland 17 August 2009 –31 August 2009

The technology of millimeter and submillimeter radio waves is a branch of Electromagnetism that is beginning to attract a growing interest in the scientific community. In the recent years, the increasingly dense use of electromagnetic spectrum forces scientists and engineers to reach new frequencies of operation for the systems. Devices operating in these bands are between the optical technologies and microwave systems. Therefore, the analysis and design of the devices is a task in the field of research and innovation. The TKK is a pioneer centre in developing this kind of technology. The department in which Alfonso Muñoz-Acevedo will carry out the stay submillimeter wave has been developed operative systems and its own technology. TKK is, thus, a clear option when choosing an investigation centre to study THz technology.

 

 

 

2008/2009

 

 

12. Sinisa Skokic, U Zagreb, Croatia to U Siena, Italy, 10 – 23 May 2009

A new analysis method will be developed, by starting from the PO code developed at the University of Siena, and the new wave-objects expansion technique, developed jointly by University of Zagreb and University of Siena. The time dedicated to the short-term scientific mission will be spent on the implementation of programmatic solutions necessary to join the two into a complete analysis method, including transformations between local and global coordinate systems, calculation of reflected wave cone from different types of reflectors, etc. Key issues from physical and numerical points of view, such as the choice of optimal surface on which the PO-field is to be computed, or optimal transformation of spatial field samples to spectral data for the wave-object expansion procedure, will also be addressed. The goal of the short scientific mission is also to extend the cooperation between the University of Siena and University of Zagreb in reflector system analysis. Furthermore, it is consistent with the scope of Sinisa’s Ph.D. studies, which focus on new analysis methods and modelling tools for reflector antenna systems.

 

11. Ruzica Golubovic, EPFL, Lausanne, Switzerland to U Belgrade, Republic of Serbia, 13 – 24 April 2009

Recently, the host and visitor institution research teams started the joint research about the nonuniformly-wound helical antennas. The first results about the nonuniformly-wound helices with the wire pigtail counterbalance will be presented at EuCap 2009 conference. The gain of the optimal nonuniformly-wound helical antenna without a reflector (with the wire pigtail counterbalance) closely parallels the gain of the classical uniformly-wound helical antenna above an infinite ground plane, while the first ones are smaller and handier. The aim of this scientific mission is to progress in the joint research of optimization of helical antennas. This have already resulted in some preliminary conference papers and a presentation in the ASSIST COST meeting. The immediate goal of this two weeks stay is to prepare a joint Journal publication. Also, the future steps of this collaboration will be decided and connected with our COST Action.

 

10. Steven Boyes, U of Liverpool, UK to SATIMO, Italy, 1 May 2009 – 10 June 2009

As SATIMO is an expert of antenna measurements and supplies advanced products to the antenna community. It is hoped that this visit will achieve the following objectives: To exchange information and ideas in this area; To use SATIMO facilities to measure a number of antennas and the results will be later used for comparison and validation of our method; To train the student in various aspects and gain experience to work in antenna industry.

 

9. Oscar Alberto Garcia-Perez, U Carlos III Madrid, Spain to ASTRON, the Netherlands, 1 April 2009 – 15 June 2009

This work is related with the planar aperture arrays design in the lower frequency band. For these aperture arrays, differentially fed antennas (i.e.: Vivaldi, Bunny-ear,…) have been mostly proposed. In this way, differential amplifiers directly connected to the antenna ports seem to be the most efficient solution in terms of noise, since they avoid the use of a lossy passive balun. These works have been presented in the last two COST meetings in Dublin and in Limassol In a more precise way, this stage deals with the design and characterization of broadband low noise amplifiers, covering the 300 MHz to 1 GHz bandwidth. Using differential amplifiers implies some interesting advantages such as interference rejection (e.g.: noise introduced by the power supply, external interferences…), higher dynamic range and reduced even-order harmonic distortion. The problem when working with differential amplifiers is that their characterization is not as easy as with the single-ended devices. Thus, some specific techniques are needed in order to obtain a correct and complete measurement of this type of amplifiers.

 

8. Belén Andrés García, U Carlos III Madrid, Spain to UCL, Belgium, 1 May 2009 – 15 June 2009

A study of different radiating elements in the 100 GHz band has to be carried out. However, the use of a Tapered Slot Antenna (TSA) as radiating element is proposed. TSA is the first option due to its performance in terms of directivity and the radiation pattern symmetry between the E and H plane, which provides a much higher resolution of each pixel than the current state of the art. The implementation of the radiating element must be compatible with the integration of the active element in order to obtain an integrated an active antenna. The Radiofrequency Group of the Universidad Carlos III de Madrid (from now on GRF) has broad experience in the topic. Several implementations of TSA at 90GHz and 348GHz in planar technology over silicon membranes, quartz and other materials have been reported. Different possibilities will be considered for the metallization study. In any case the use of gold with 2 microns thickness is assumed. The proposed study will be done with the Method of Moments numerical method that has been developed for years by the group of Prof. Christophe Craeye from Université Catholique in Louvain la Neuve, Belgium.

 

7. Daniele Pinchera, U Naples, Italy to AUTH Thessaloniki, Greece, 29 March 2009 – 5 April 2009

Direct radiating arrays are potentially a suitable and interesting alternative to reflector antennas for satellite communications. On the other side, usual array architectures and design methods present a number of draw backs. In particular, the stringent radiating constraints have to be satisfied with a number of (isophoric) amplifiers and phase shifters as small as possible – and this constitutes a synthesis problem hard to solve. The main purpose of this short mission is the consolidation of a novel approach, developed by the CNIT (Italian National Institute for Telecommunications), in particular the research units of Naples and Reggio Calabria, and the Aristotle University of Thessaloniki in the framework of an ESA contract, that should be able to effectively face the synthesis problem. The assessment of the synthesis strategy will be obtained by means of the realization and testing of numerical codes implementing the aforementioned method, and the design of some preliminary array layouts. The short term mission would be also very useful to consolidate the relationship between the Italian and Greece research groups and would be the starting point for a number of future missions with the purpose of exchanging knowledge between the involved institutions.

 

6. Rafal Glogowski, IST Lisboa, Portugal to EPFL Lausanne, Switzerland, 4 – 16 May 2009

A PhD program in new materials for printed antennas is starting now. This is a very hot topic where materials of very different types can be used as substrates and superstrates of printed antennas. The range of applications go from antennas printed on clothes (wearable antennas) to antennas printed on transparent materials (building and car windows), on semiconductors (solar cells), on wood or even on the more exotic electromagnetic bandgap (EBG) materials and other metamaterials. With this short-term scientific mission the applicant aims at get acquainted with the work done at EPFL on this topic. The following goals are envisaged: Understand what the constraints and challenges of designing antennas to be printed on new materials like solar cells; Get direct contact with the advanced solar antenna modules; Discuss what are the opportunities of doing modelling and experimental work in this new field; Discuss what are the perspectives of application of new antenna materials in the space industry.

 

5. Aki Karttunen, Helsinki TU, Finland to IETR Rennes, France, 16 March 2009 –15 May 2009

The work to be carried out is part of a project entitled “Broadband multi-antenna radios for millimetre wave frequency bands (BRAWE)”. The objective is to design lens antennas for E-band point-to-point and point-to-multipoint communications. The main requirements for these antennas are high gain (from 30 dBi up to 38 dBi) and beam scanning capability. The feed antenna array is given and a lens needs to be designed. The lens design begins by studying a standard extended hemispherical lens, but the final design will be a synthesised shaped lens. The same ray-tracing method has previously been used to synthesise dual reflector feed systems for hologram-based CATR at 310 GHz and 650 GHz.

 

4. Qi Luo, U. Aveiro, Portugal to Brno TU, Czech Republic, 2 – 20 March 2009

This short term mission is meant to give the Applicant the opportunity to be in contact with the approaches used in the group of Professor Zbynek Raida in the field of Metallic Electromagnetic Band Gap (EBG) materials. The goal is to provide to the Applicant the opportunity to learn more about the electromagnetic properties that these new materials exhibit. Mainly, to further understand some theoretical concepts related to these structures and, if possible, to investigate their possible applications in the design of low profile antennas for wireless communications. Furthermore, this short term mission maybe also an opportunity to discuss alternative single and multiband patch antenna configurations using Fractal geometries, that can be later proposed, discussed and investigated.

 

3. Martin Štumpf, Brno TU, Czech Republic to TU Delft, the Netherlands, 23 February 2009 – 20 March 2009

The frequency domain integral equation techniques of antennas on planarly layered substrates require the difficult and computationally intensive evaluation of Sommerfeld integrals. In a conventional approach of the transient analysis, Sommerfeld integrals are evaluated for each source/observer distance and frequency step, and then transformed through the discrete Fourier transform, making the time-domain analysis cumbersome. For these reasons, the exploitation of the joint transform techniques such as Cagniard-de Hoop method is expedient, which exhibits a high efficiency and accuracy. In the frame of my short-term mission, time-domain Green’s functions should be derived for several types of planarly layered media considering horizontally and vertically oriented unit electrical dipoles. Then, the stable time-domain method of moments (MoM) algorithm should be developed. The approximations of time-domain Green’s functions, valid for the small source/observer distances especially, shall be investigated.

 

2. Marko Sonkki Oulu, Finland to TU Valencia, Spain, 1 January 2009 – 28 February 2009

The work plan for the STSM period is a continuation of Mr. Sonkki´s research exchange from University of Oulu to Technical University of Valencia. The exchange period has been taken place from April 2008 to December 2008. The financing for the research exchange has been received from project AATE (Adaptation of Antennas to Usage Environments), which is funded by Tekes (Finnish Funding Agency for Technology and Innovation). In the project Telecommunication Laboratory and Microelectronics and Material Physics Laboratories from University of Oulu, and SMARAD (Centre of Excellence in Smart Radios and Wireless Research) from Technical University of Helsinki are involved. The exchange takes part of the project Antenna Design Using Characteristic Mode Theory in Technical University of Valencia. The purpose of the exchange is to open new high level mobile antenna research cooperation between the universities.

 

1. Carlos Martínez-Raposo Villar, TU Delft, the Netherlands to IMST GmbH, Germany, 3 – 7 November 2008

The one-week visit of the Applicant to IMST is envisaged in the frame of a joint activity between TU Delft (IRCTR) and IMST GmbH in the field of technological implementation of innovative antenna architectures. The final goal for the project is to manufacture an integrated LTCC (Low Temperature Cofired Ceramics) module hosting a small array composed of six aperture-type antennas. The power distribution network should be integrated in the multilayer structure. This will be possible by using LTCC technology.

 

 

 

2007/2008

 

 

10. Sinisa Skokic, Univ. Zagreb to TNO, The Hague, 15 – 29 June 2008

Investigate concepts for polarising sheets and “dual-gridded” reflectors for circular polarisation. Modify proposed solutions for polarising sheets in order to fulfil the satellite system level requirements, analyze the proposed solutions using suitable EM solvers, both in-house developed and commercial ones, and modify the proposed solutions in order to obtain structures that do not contain dielectrics, suitable for space applications. The objective of the STSM is also to extend the cooperation between TNO and Univ. Zagreb in reflector analysis analysis which forms part of Sinisa’s PhD studies.

 

9. Tomasz Maleszka, Wroclaw Univ. Technology to DTU, Lyngby, 15 – 29 June 2008

Determine the technical requirements for accomplishing a suboptimal (quasi-omnidirectional) coverage of a combined radiation pattern of the Moon Orbiter S-band antenna. Perform electromagnetic simulations and measurements of the combined radiation pattern and polarisation properties of the antenna system mounted on a full-scale mockup of the Moon Orbiter in the DTU spherical near-field facility.

 

8. Thomas Bertuch, FGAN/FHR to POLITO, 9 – 27 June 2008

Apply a new regularisation technique for 3D singular integral equations developed at POLITO to a MoM solution for printed conductors on circularly cylindrical substrates with a metal backing. The new method is based on a mesh-adapted windowing of the spectral Green's function of the background medium before numerically computing by the inverse Fourier transform the spatial Green's function, which, due to this treatment, will be regular at its origin.

 

7. Jaroslav Lacik, Brno Univ. Technology to TU Delft, 26 May 2008 – 6 June 2008

Compose antenna parameters in non-covential domains, viz. Mean-value Parameters (MVP) and Frequency-domain Parameter Transforms (FDPT). Both TUD and BUT developcurrently time-domain approaches. The mission will exchange experiences, verify results, discuss further steps, and prepare common activities.

 

6. F. Muge Tanyer-Tigrek, Delft Univ. Technology to Univ. catolique Louvain, 5 –23 May 2008

Research the magnetic wall concept in order to convert small wideband bi-directional antenna into uni-directional ones, by maintaining a wide operating band and a small antenna height, as far as possible.

 

5. Luis Enrique García-Muñoz, Univ. Carlos III to Univ. Catolique Louvain, 1 May 2008 – 1 June 2008

Use finite and infinite-array simulators to compute special phenomena related to scan blindness, extend the finite arrays studies to very large arrays, i.e. more than 15x15 elements, without placing explicitly unknowns on all elements, but keeping in mind complex elements. Also, a study about noise and noise coupling in arrays (cf. several publications by the UCL group) is of interest. A future cooperation was agreed focusing on numerical methods for truncated arrays by using Array Scanning Methods and Macro Basis Functions with the UCL MOM code.

 

4. Francisco Javier Herraiz-Martinez, Univ. Carlos III Madrid to EPFL, Lausanne, 27 April 2008 – 10 May 2008

Analyse microstrip patch antennas partially filled with Left-Handed (LH) cells based on Sievinpiper mushrooms. A transmission model is available in Madrid, but is needs to be supplemented by the models available at EPFL. Current commercial solvers are inadequate.

 

3. Pekka Alitalo, TKK, Helsinki to EPFL, Lausannne 31 March 2008 – 4 April 2008

Prepare for a full visit to EPFL June - December 2008 with research in the area of metamaterials, e.g. for electromagnetic cloaking and matching of microwave lenses - expected to become increasingly important areas for future ISTs.

 

2. Peter Kovács, Brno Univ. Technology to IMST, Kamp-Lintfort, 3 – 21 March 2008

Perform a study on optimisation of a GALILEO antenna with a metamaterial substrate. The objective is to replace the conventional mushroom structure (with vias) with a planar one (without vias) focusing on their AMC and EBG properties. A number of areas for future cooperation were identified and joint publication of results was agreed. Currently the planar structure has very narrow bandwidths.

 

1. Yuri Álvarez López, Univ. Oviedo to DTU, Lyngby, 20 November 2007 – 15 December 2007

Perform comparisons between the Sources Reconstruction Method (SRM) of Univ. Oviedo and the combination of the Spherical Wave Expansion and Planar Wave Expansion (SWE/PWE) of DTU. A reference antenna (offset reflector) was measured in four configurations and the two methods showed good agreement. During the last part of the stay Yuri Lopez followed the ESA CO-SMOS L-band antenna measurement campaign. A paper was presented at the workshop in Limassol.