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Date/Time: Saturday May 21 2011 2:00 - 4:00 pm
Topic #1: Near-field Phenomena in EMC Applications
by Prof. Alireza Baghai-Wadji
RMIT University Melbourne, Australia
alireza.baghai-wadji@rmit.edu.au
Topic #2: Different Requirements of FCC/IC/CE Rules or Standards for Short Range Devices
by Mr. Wailand Zhang
American TCB Holding International (Shenzhen) Limited
Wailand@acbcert.com
Venue:
上海大学延长路校区
广中路788号(延长路149号)
Near-field Phenomena in EMC Applications
Prof. Alireza Baghai-Wadji
RMIT University, Melbourne, Australia
Abstract:
The application of the popular Method of Moments (MoM) to three-dimensional (3D) electromagnetic near-field problems is typically plagued by a number of computational difficulties which may severely obscure the accuracy of the resulting numerical data and their interpretation. The roots for these difficulties are strong- and hyper-strong singularities of the involved dyadic Green’s functions (GFs) and their spatial derivatives obtained in the direction normal to the bounding surface of the problem of interest. Conventionally, the GFs are first constructed in spatial domain and then their near-field asymptotic expansions are determined - a procedure which is inherently susceptive to large numerical errors whenever the GFs are not available in closed-form. The resulting (spatial domain) near-field asymptotic terms are finally used to calculate the so-called self-action terms and the terms describing the interaction between closely-located boundary elements.
In this presentation an alternative procedure will be proposed which allows the computation of self-action and interaction terms easily, robustly and accurately, and thus, responds to the shortcomings innately present in conventional techniques. The method permits gaining deep insight into the nature of the near-fields in general and consists of a number of easy-to-implement steps which can be automated straightforwardly, irrespective of the availability of the involved dyadic GFs in closed-form. The proposed method comprises the following steps: (i) Diagonalise Maxwell’s equations with respect to a chosen direction in space. (ii) Transform the resulting equations into the wave-number domain (W-domain). (iii) Utilise a novel procedure, proposed in this presentation, for the determination of the asymptotic expansions of the eigenpairs in W-domain. (iv) Employ the resulting terms and construct the asymptotic GFs in W-domain. It is this step which constitutes the basic result of the presentation: We observe that certain “unwanted” terms cancel out automatically already in W-domain, a property which is referred to as the “natural regularisation.” A plausible physics-based explanation for this effect will be provided. Furthermore, a relationship will be established between this effect and the near-fields in spatial domain. (v) Beside natural regularisation further schemes will be introduced to handle the remaining singularities. (vi) The W-domain asymptotic terms of the eigenpairs enable the construction of asymptotic expansions of the GFs in W-domain. (vii) The resulting functions, which can be transformed into real-space simply-by-inspection, constitute the spatial domain near-field asymptotic expansion terms of GFs.
The above steps will be illustrated in terms of solving 3D Maxwell’s equations in isotropic media. Furthermore, applying the reciprocity theorem we shall obtain near-field distribution for dipoles being oriented normal to an interface.
Using the above theory, Universal Functions (UFs) will be introduced for the calculation of interaction elements in MoM applications. The UFs need to be calculated only once and can be utilised for arbitrary geometry and frequencies. It turns out that UFs are extraordinary smooth and thus convenient for data processing and storage.
It will be shown that the application range of the proposed method is not limited to EMC problems. Furthermore, wherever conventional approaches perform rather poorly in anisotropic media, the proposed method powerfully maintains its dominance. The method also applies to problems with scales ranging from space antennas to nano-antennas.
The presentation is self-contained and develops all the required tools and means during the lecture. The presentation concludes with a discussion of ideas for possible future extension of the method.
EMC Shanghai Chapter Seminar
About the Speaker:
Alireza Baghai-Wadji is currently professor of electronic and computational engineering at RMIT University, School of Electrical and Computer Engineering, Melbourne, Australia, and an international representative of his university in the Far- and South East Asia, and in the Middle East. Since 2005 he has frequently represented his university in these regions in matters of education and research. He is also a distinguished professor at the Centre of Electromagnetic Simulation, Beijing Institute of Technology, Beijing, China.
He has received his MSc (communication engineering), PhD (computational electronics), and Doctor of Science (physical electronics) in 1984, 1987 and 1994, respectively, from Vienna University of Technology (VUT), Vienna, Austria. In 2003 he was awarded Doctor of Science in quantum electronics and materials science from Helsinki University of Technology (HUT), Helsinki, Finland. Prior to joining RMIT University in March 2005 he was 1979-2005 with the Department of Electrical and Information Technology at VUT: associate professor (1997-2005), docent (1994-1997), assistant professor (1988-1994), research fellow (1984-1988), and research associate (1979-1983).
He has lived and worked on four continents accumulating vast experience in both academia and high-industry: visiting professor at HUT (Jan. 2009); visiting scientist at the Max Planck Institute (Quantum Optics), Garching, Germany, (July 2009); consultant to EPCOS, Munich, Germany (since 2004); visiting professor at HUT for one-and-a-half year (1999, 2000, and 2004); Nokia fellow in (2000); visiting professor at the Institute for High Performance Computing (IHPC) in Singapore and a senior member of the Institute for Mathematical Sciences (IMS) in Singapore for four months (Jan., Feb., Oct., Nov. 2003). He was three times the recipient of the prestigious Austrian Kurt Goedel research fellowship enabling him to spend a total of ten months at the University of California, Irvine, USA (1990, 1991, and 1992); he was adjunct professor in the Department of Statistics and Mathematics at the Arizona State University, Tempe, Arizona, USA (1995-2004); principal engineering consultant with Motorola, Scottsdale, Arizona, USA (1994-1999); principal engineering consultant with Siemens Matsushita, Graz, Austria (1990-1994); consultant with Siemens, Munich, Germany (1983-1990). He was director of the Aerospace and Aviation Electronics Program at The Sir Lawrence Wackett Aerospace Centre (2007-2008), Melbourne, Australia. He is an honorary member and fellow of The Electromagnetics Academy, USA and has been listed in Who's Who in Electromagnetics, USA. He is also listed in Marquis Who's Who in the World (Editions 2009-2011). Since 1997 he has been an associated editor for IEEE-UFFC Transactions. He was twice a guest editor for the IEEE-UFFC Transactions, editing special issues devoted to the Design, Modeling, Simulations and Optimization Techniques in Micro-acoustic Devices. He has more than 140 publications in reviewed journals and conference proceedings, and has delivered more than 70 invited speeches internationally. He is the owner of one patent in USA.
He has instructed 20 half-day or full-day popular short courses at IEEE sponsored conferences since 1994.
Since 1979 he has been fascinated by and contributed to the ab-initio and first-principle computational engineering for the high-tech industry, with applications in as varied areas as electromagnetics, micro-acoustics, micro-electronics, photonics, quantum electrodynamics, and quantum optics.
In the past decade he has become deeply interested in the philosophy and history of science and has been lecturing widely on atomistic and holistic thinking, innovative and creative problem solving methodologies, quantum indeterminacy, spontaneity, and formation of consciousness. His lectures on modern research methodologies, epistemology, and scientific strategic thinking are particularly-well received in China and elsewhere in the Far- and South East Asia.
EMC Shanghai Chapter Seminar
Different Requirements of FCC/IC/CE Rules or Standards
for Short Range Devices
Mr. Wailand Zhang
American TCB Holding International (Shenzhen) Limited
About the Speaker:
EM
POSITION
ACB Examining Engineer
Technical Support Manager in China
QUALIFICATION
iNARTE Certified EMC Engineer(No. EMC-003183-NE)
IEEE Member
EXPERIENCE
EMC/RF Technical Supervisor
2003 – 2005
ITE/ISM/Auto EMC Testing, SRD/Low-power device RF Testing.
Examining Engineer
2005 –Present
Unintentional/ Intentional Radiators Review for FCC/IC Application. |
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