Rad Lab Seminar

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Friday Feb. 21, 2003, 12:30 -1:30 PM
Room # 1005 EECS

Tapan K. Sarkar
Syracuse University
IEEE Distinguished Lecturer

 

Generation of Broadband Electromagnetic Response
from DC to Daylight on Your PC


In traditional computational electromagnetics, analysis is carried out exclusively in either the time or in the frequency domain. Most of the popular methods for performing the analysis in the time domain (finite-difference, finite-element or integral equation) solve either the integral or the differential form of Maxwell’s equations in the time domain. The way to analyze electrically large problems is to then use a bigger and a faster computer. In the frequency domain, one employs essentially the same way of thinking. Here, Maxwell’s equations are solved entirely in the frequency domain by utilizing one of the above popular methods. Unlike in the time domain, here one needs to solve a matrix equation, which becomes large as the electrical dimensions of the structure increases. The methodology for analyzing electrically large problems is to then use a supercomputer, as one needs to solve a large matrix equation. Even though extrapolation techniques like the Matrix Pencil (in the time domain) or the Cauchy method (in the frequency domain) to name a few, have been applied with success, these methods cannot extrapolate the information accurately for all classes of problems. Hence, a new methodology is presented which will be numerically stable and computationally efficient under all circumstances.

Utilizing early time and low frequency data, the complete electromagnetic response of any object, however electrically large it may be, can be generated. The low frequency and the early time data contain mutually complementary information. By using this mutually complementary data, simultaneous extrapolation in time and frequency domains are carried out. It is important to point out that in this procedure no new information is created but existing information is processed in a novel fashion. This simultaneous extrapolation in time and frequency domains is carried out through the use of the Associate Hermite Polynomials. The interesting property of the Hermite polynomials is that they are the eigenfunctions of the Fourier Transform operator. This implies that if the time domain response from any electromagnetic object at a point in space is modeled by an Associate Hermite Series expansion, the frequency domain response at the same point can be expressed as a scaled version of the same time domain representation. Therefore using early time and low frequency domain response data, it is possible to reproduce the missing response in both the domains. Examples will be presented to illustrate the efficiency and accuracy of this methodology.


Biography
Prof. Tapan K. Sarkar
Department of Electrical &
Computer Engineering
Syracuse University
121 Link Hall
Syracuse, New York 13244-1240
Tel: +1 (315) 443-3775
Fax: +1 (315) 443-4441
E-mail: tksarkar@mailbox.syr.edu
Home page: http://web.syr.edu/~tksarkar

 

Tapan Kumar Sarkar received the B. Tech. degree from the Indian Institute of Technology, Kharagpur, India, in 1969, the M.Sc.E. Degree from the University of New Brunswick, Fredericton, Canada, in 1971, and the M.S. and Ph.D. degrees from Syracuse University; Syracuse, New York in 1975.

From 1975 to 1976 he was with the TACO Division of the General Instruments Corporation. He was with the Rochester Institute of Technology, Rochester, NY, from 1976 to 1985. He was a Research Fellow at the Gordon McKay Laboratory, Harvard University, Cambridge, MA, from 1977 to 1978. He is now a Professor in the Department of Electrical and Computer Engineering, Syracuse University; Syracuse, NY. His current research interests deal with numerical solutions of operator equations arising in electromagnetics and signal processing with application to system design. He obtained one of the "best solution" awards in May 1977 at the Rome Air Development Center (RADC) Spectral Estimation Workshop. He has authored or coauthored more than 210 journal articles and numerous conference papers and has written chapters in 28 books and ten books including the latest one "Iterative and Self Adaptive Finite-Elements in Electromagnetic Modeling" which was published in 1998 by Artech House.

Dr. Sarkar is a registered professional engineer in the State of New York. He received the Best Paper Award of the IEEE Transactions on Electromagnetic Compatibility in 1979 and in the 1997 National Radar Conference. He received the College of Engineering Research Award in 1996 and the chancellor’s citation for excellence in research in 1998 at Syracuse University. He was an Associate Editor for feature articles of the IEEE Antennas and Propagation Society Newsletter, and he was the Technical Program Chairman for the 1988 IEEE Antennas and Propagation Society International Symposium and URSI Radio Science Meeting at Syracuse. He is on the editorial board of Journal of Electromagnetic Waves and Applications and Microwave and Optical technology letters. He has been appointed U.S. Research Council Representative to many URSI General Assemblies. He was the Chairman of the Intercommission Working Group of International URSI on Time Domain Metrology (1990-1996). Dr. Sarkar is a member of Sigma Xi and International Union of Radio Science Commissions A and B. He received the title Docteur Honoris Causa from Universite Blaise Pascal, Clermont Ferrand, France, in 1998.