Asymptotic Considerations in Early-Time Response Computation

 

Abstract

Transform techniques together with linear response theory are routinely being applied to obtain the time-domain solutions to problems in electrical engineering.  For systems that can be represented by lumped elements, Elmore's method provides an efficient means for estimating signal delay and rise time.  In distributed environments with dissipation,  numerical solutions are often the only way to obtain accurate results.  The numerical Bromwich integration and the singularity expansion method belong to this category.  By incorporating properly chosen asymptotic forms of the response function in the frequency domain, the inverse transform can be obtained with considerable savings in computational effort, especially in the early-time region.  Applications of the formulation to the computation of the transient response of high-speed devices, distributed amplifiers, and the dielectric sphere excited by an incident electromagnetic wave will be presented.

Biography

      Thomas Wong received the B.Sc. degree from the University of Hong Kong, and the M.S. and Ph.D. degrees from Northwestern University, all degrees being in electrical engineering.  In 1981 he joined the Illinois Institute of Technology, where he is now a professor in the Electrical and Computer Engineering Department.  From 1987 to 1995, he was the graduate program director in ECE and in the 1998-1999 academic year he was the chair of the University Faculty Council.  He has conducted research in microwave measurement, charge transport in solids, propagation effects in high-frequency devices and integrated circuits, transient electromagnetics, nonlinear device measurement, and broadband wireless systems.  He is a former chair of the IEEE Chicago joint chapter of APS and MTTS, and served on the organizing committees of a number of international conferences.  He is the author of Fundamentals of Distributed Amplification (Artech, 1993) and has several patents on microwave electronics and wireless system design.