EMCABS: 01-05-2011

BROADBAND PERMEABILITY MEASUREMENT METHOD FOR FERRITES AT ANY MAGNETIZATION STATE: DIRECT PROBLEM
Jorge E. Lezaca, Patrick Qu´eff´elec, and Alexis Chevalier
Lab-STICC UMR 3192, European University of Brittany, University of Brest, Brest, France
Proceedings of the 40th European Microwave Conference, 28–30 September, 2010, Paris, France, pp.148–151.
Abstract: A data processing program based on a full-wave electromagnetic (EM) analysis of a non-reciprocal transmission line partially filled with a ferrite sample is presented. A predictive permeability tensor model is introduced in the Maxwell equations to allow the program to work at any magnetization state. The dispersion diagram for the first significant modes inside the ferrite loaded region of the line is obtained. The presence of magneto static modes generated by magnetized ferrite inside the line is verified. Using a mode matching technique, the theoretical scattering parameters (S-parameters) of the non-reciprocal transmission line are calculated. The analysis is validated by the comparison between the calculated S-parameters with those obtained with a FEM based EM simulator and the measurements at limit cases.
Index terms: Ferrite, permeability, measurement method.

EMCABS: 02-05-2011

PRECISE CHARACTERIZATION AND DESIGN OF COMPOSITE ABSORBERS FOR WIDEBAND MICROWAVE APPLICATIONS
Anjali Sharma, Nahid Rahman, Mahmut Obol, Mohammed Afsar
High Frequency Materials Measurement and Information Centre, Dept. of Electrical and Computer Engineering, Tufts University, Medford, MA-02155, USA
Proceedings of the 40th European Microwave Conference, 28–30 September, 2010, Paris, France, pp. 160–163.
Abstract: This paper presents a novel measurement, characterization, and design procedure for practical broadband absorbers. A multi-layer absorber ideally suited to broadband communication applications has been designed, optimized and analyzed. A newly developed and precise transmission-reflection (T/R) based waveguide measurement technique has been used to determine the frequency dependent complex permeability and permittivity of a variety of dielectric and magnetic absorbers in the microwave spectra. These materials have been accurately characterized for the first time across eight frequency bands from 2 to 40 GHz. The constitutive parameters have then been analyzed to design a 2-18 GHz multi-layer composite structure that offers minimum ­specular reflection and maximum absorption of electromagnetic energy across the ­bandwidth. To verify the absorption performance in wideband applications, the multi-layer structure has been inserted in the lossy cavity of a 2-arm Archimedean spiral antenna and simulated for its radiation patterns. The optimal thicknesses of each absorbing layer have been determined for this specific broadband application. Finally, the reflection properties of the composite structure have been experimentally verified using the T/R measurement technique.
Index terms: Composite absorber, wideband, measurement method.

EMCABS: 03-05-2011

SIMPLIFIED METHOD FOR MEASURING SAR BY USING PHANTOM COMPOSED OF WAVE ABSORBER
Tan Watanabe, Naobumi Michishita, Yoshihide Yamada
Department of Electrical and Electronic Engineering, National Defense Academy, Japan
Proceedings of the 40th European Microwave Conference, 28–30 September, 2010, Paris, France, pp. 216–219.
Abstract: A simplified method for measuring the specific absorption rate (SAR) is required in order to limit the spatial average SAR for mobile devices in Japan. In this paper, a simplified SAR measurement method involving the use of a flat plane lightweight phantom composed of a radio wave absorber is proposed. The utility of the lightweight phantom and the feasibility of using the proposed measurement method along with the lightweight phantom are verified. Finally, the peak spatial average SAR is estimated by using the proposed measurement method.
Index terms: SAR, mobile device, measuring method.

EMCABS: 04-05-2011

SAR COMPUTATION IN A REAL-SIZED CAR: MULTI-EXPOSURE SCENARIOS
Louis-Ray Harris, Maxim Zhadobov, and Ronan Sauleau
Institute of Electronics and Telecommunications of Rennes (IETR), Rennes, France
Proceedings of the 40th European Microwave Conference, 28–30 September, 2010, Paris, France, pp. 224–227.
Abstract: In this study, investigations have been carried out into the variation of whole-body averaged SAR values for four humans (one driver + three passengers) inside a realistic realized car. Transmitting devices used in the simulations had multiple frequencies making it a multi-exposure environment. These devices (e.g. Bluetooth, Universal Mobile Telecommunications System (UMTS) and WiMAX) use differing operating frequencies and can be used in semi-echoic environments such as cars, trains, planes, etc. Results showed that the whole-body averaged SAR is below exposure limits provided by international standards and guidelines when there is one of each transmitter present. The results also show the whole-body averaged SAR when two active transmitters are simultaneously in use. Computed values are shown to be within the ICNIRP recommended limits.
Index terms: SAR, multi-exposure, car.

EMCABS: 05-05-2011

EFFECT OF VIA STUBS ON THE TRL CALIBRATION TECHNIQUE FOR MEASUREMENT OF EMBEDDED MULTILAYER STRUCTURES
Miroslav Kotzev, Heinz-Dietrich Brüns, and Christian Schuster
Institut für Theoretische Elektrotechnik, Technische Universität Hamburg-Harburg, Hamburg, Germany
Proceedings of the 40th European Microwave Conference, 28–30 September, 2010, Paris, France, pp. 248–251.
Abstract: In this paper the effect of access via stubs on the Thru-Reflect-Line (TRL) calibration for de-embedding of multilayer printed circuit board structures is analyzed. For this purpose a dedicated calibration board with single ended TRL standards containing broadband signal launches for measurement of embedded (internal) printed circuit board (PCB) structures such as striplines and vias (plated through holes) was designed. First results from the extracted signal launch S-parameters in the bandwidth from 40 MHz to 40 GHz using two-tier calibration techniques are shown and corroborated using full-wave 3-D FEM solver models. It was found that the access via stubs represent highly resonant structures that act as short circuits at their quarter wavelength frequency (and odd multiples thereof). As a consequence, the TRL algorithm fails at these frequencies and the calibration cannot be accomplished. Several mitigation strategies such as using recessed probing or backdrilling are discussed and their extension of calibration bandwidth is quantified.
Index terms: PCB, TRL, calibration, via stubs.

EMCABS: 06-05-2011

INTER-CHIP AND INTRA-CHIP PULSED SIGNAL TRANSFER BETWEEN TRANSMITTING AND RECEIVING LOOPS IN WIRELESS INTERCONNECT CONFIGURATIONS
+ Loan E. Lager, and ++ Adrianus T. de Hoop
+ IRCTR, Delft University of Technology, Delft, the Netherlands
++ Laboratory of Electromagnetic Research, Delft University of Technology, Delft, the Netherlands
Proceedings of the 40th European Microwave Conference, 28–30 September, 2010, Paris, France, pp. 577–580.
Abstract: The pulsed signal transfer between transmitting and receiving loops employed for inter-chip and intra-chip wireless interconnects in integrated circuit devices is investigated. A computational model, based on the electromagnetic reciprocity theorem of the time-convolution type, is developed. The transmitter loop excitation is modeled as a causal, unipolar pulse characterized by its pulse amplitude, its pulse rise time and its pulse time width. Analytic expressions are provided for the generator voltage in the equivalent Th´evenin circuit describing the performance of the receiver loop in its dependence on its location relative to the transmitter loop. Due to the intricate radiation behavior of the coupling magnetic field, the received signal is in an intricate manner related to the signal to be transferred. Numerical examples illustrate the complexity of the phenomena involved.
Index terms: Wireless interconnector, inter-chip, signal transfer.

EMCABS: 07-05-2011

APPLICATION OF TRANSIENT ELECTROMAGNETIC FIELD SIMULATION WITH FINITE ELEMENTS
M.H. Vogel, H. Songoro, M.H. Commens
ANSYS, Inc., Pittsburgh, PA, USA
Proceedings of the 40th European Microwave Conference, 28–30 September, 2010, Paris, France, pp. 581–584.
Abstract: This paper presents a full-wave 3D electromagnetic transient simulation method developed around an unstructured finite-element mesh. In such an unstructured mesh, the elements have a range of sizes and orientations such that, rather than forming a regular grid, they conform to the geometry of the model, respecting all its details. This paper discusses the method and presents some examples of applications.
Index terms: Numerical method, FEM, transient, EMP pulse.

EMCABS: 08-05-2011

MEASUREMENT MAGNETIC FIELD LEVEL OF RADIATED EMISSIONS FROM MILITARY EQUIPMENT
Rafał Przesmycki, Leszek Nowosielski, Marian Wnuk, Roman Kubacki
Faculty of Electronics, Military University of Technology, Warsaw, Poland
Proceedings of the 40th European Microwave Conference, 28–30 September, 2010, Paris, France, pp. 1285–1288.
Abstract: This paper addresses problems of electromagnetic compatibility of military equipment. Its goal is to present a sample application of position and methodology of measurements concerning the measurement level of magnetic induction of interference in the frequency range from 30 Hz to 100 KHz, generated by equipment, sets of devices and such components as feeder cables, control, signal, aerial and connection cables(ducts) between components of military equipment sets. The procedure can also be used with reference to basic operating frequency of sonars, industrial devices, scientific and medical equipment. The procedure cannot be used with reference to emission directly from antennas and emission at the basic frequency of radio communication transmitters. The paper presents the methodology of measurements and description of position for measuring the magnetic induction level of interference in the frequency range from 30 Hz to 100 kHz according to the RE101 procedure of the MIL-STD-461E standard. The goal of research is to obtain measurement data essential for assessment of compatibility of tested equipment or sets of devices with requirements included in the defense standard MIL-STD-461E. The above mentioned position is used for conducting research in the Laboratory of Electromagnetic Compatibility, Faculty of Electronics, Military University of Technology, which has accreditation granted by the Polish Accreditation Centre.
Index terms: Radiated emission, magnetic field, military equipment.

EMCABS: 09-05-2011

DESIGN OPTIMIZATION OF AUTOMOTIVE ELECTRONIC CONTROL UNIT USING THE ANALYSIS OF COMMON-MODE CURRENT BY FAST ELECTROMAGNETIC FIELD SOLVER
+ Yuji Okazaki, + Masaki Unno, ++ Takanori Uno, and + Hideki Asai
+ Graduate School of Engineering, Shizuoka University, Hamamatsu-shi, Japan.
++ DENSO CORPORATION, Kariya-shi, 448-8661 Japan
Proceedings of the 40th European Microwave Conference, 28–30 September, 2010, Paris, France, pp. 1289–1292.
Abstract: In this paper, the authors propose an optimization system based on the fast electromagnetic field solver and met heuristics for reducing electromagnetic interference (EMI) on an electronic control unit (ECU). They adopt simulated annealing (SA), genetic algorithm (GA) and taboo search (TS) to seek optimal solutions, and the finite difference time domain (FDTD) method with general purpose computing on a graphic processing unit (GPGPU) to analyze electromagnetic fields. Therefore, the proposed system can determine the adequate combination of the values of discrete circuit components and the width of layout patterns on a printed circuit board (PCB) efficiently and practically, to reduce EMI caused by the common-mode current. Finally, the authors apply the proposed system to an example circuit to verify the validity and efficiency of the system.
Index terms: Automotive, EMI, common mode current.

EMCABS: 10-05-2011

EFFECT OF NONLINEAR PORT IMPEDANCES ON DISTRIBUTED PASSIVE INTERMODULATION IN PRINTED LINES
Alexey Shitvov, Dmitry Zelenchuk, Alexander Schuchinsky
The Institute of Electronics, Communications and Information Technology (ECIT), Queen’s University Belfast, Belfast, UK
Proceedings of the 40th European Microwave Conference, 28–30 September, 2010, Paris, France, pp. 1293–1296.
Abstract: The effect of weak nonlinear terminations on the distributed passive intermodulation (PIM) generation in printed transmission lines has been investigated. The phenomenology based on the nonlinear transmission line model developed in the previous work has been generalized by introducing the new nonlinear boundary conditions. The developed model has been verified experimentally with the loose end connectors emulating weak nonlinear source/load impedances. Comparison of the measurement and simulation results has proved that the presented model enables an accurate evaluation of the effect of the lumped nonlinearities on the distributed PIM generation in printed circuits.
Index terms: PCB, transmission line, intermodulation distortion.

EMCABS: 11-05-2011

INTERACTION OF LOW FREQUENCY MAGNETIC FIELDS WITH THIN 3D SHEETS OF COMBINED RESISTIVE AND MAGNETIC PROPERTIES
+ R. Jobava, + A. Gheonjian, + D. Karkashadze, and ++ J. Hippeli
+ Electrical and Electronics Engineering Department, Tbilisi State University, Tbilisi, Georgia
++ AUDI AG, Ingolstadt, Germany
Proceedings of the 40th European Microwave Conference, 28–30 September, 2010, Paris, France, pp. 1309–1212.
Abstract: The subject of this paper is numerical modeling of thin 3D sheets with combined resistive and magnetic properties, exposed by low frequency magnetic fields. Incorporating ­reduction of thickness of sheet into Maxwell equations leads to approximate boundary conditions, written for tangential electric and magnetic fields of free space. These fields are represented only by vector potential, which is calculated based on single and double layer currents, located on the interface surface. Resulting equations are solved via Method of Moments. Numerical simulations are compared with semi-analytic solutions for thin plate and for spherical shell, as well as with measurement data. As an application, radiation from a supply cable in the presence of a metallic surface and shield is considered.
Index terms: Low frequency, shielding, interaction.

EMCABS: 12-05-2011

DESIGN OF WEARABLE COMMUNICATION DEVICE FOR BODY PROTECTION FROM EM WAVE USING THE EBG STRUCTURE
Sang il Kwak, Dong-Uk Sim, Jong Hwa Kwon and Hyung Do Choi
Radio Technology Research Department, ETRI (Electronics and Telecommunications Research Institute), Daejeon, Korea
Proceedings of the 40th European Microwave Conference, 28–30 September, 2010, Paris, France, pp. 1433–1436.
Abstract: This paper presents a wearable communication device for body protection from electromagnetic waves using an electromagnetic bandgap (EBG) structure at a WCDMA band. Since wearable wireless communication devices are used in the proximity or contact of the human body, a health risk from electromagnetic fields generated by body worn devices is important. The EBG structures can suppress the propagation of surface current and act as a perfect magnetic conductor. Thus, it is capable of preventing an undesired electromagnetic wave from the wireless communication devices. The proposed wearable communication device has the PIFA with the EBG structure at a WCDMA band, frequency generator for the SAR testing and a dielectric case. It is similar to a watch phone worn on the human wrist. Simulation and experimental results demonstrate S parameter, radiation pattern and the SAR value of the proposed structure.
Index terms: Wearable device, SAR, EBG.

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