题目：Direct Optimal Synthesis of Microwave Bandpass Filters with A General Loading Effect
时间：2012年8月22日15:30
地点：主楼3区241
报告人：Ke-Li Wu
单位：Dept. of Electronic Engineering,  The Chinese University of Hong Kong

Abstract: This talk will present an analytical approach to the synthesis of a general Chebyshev filter that matches to a frequency variant complex load at one port and a real constant load at the other port based on power wave renormalization theory under two practical assumptions: (1) the prescribed transmission zeros are stationary; and (2) the reflection zeros are located along imaginary axis. Three necessary conditions that stipulate the characteristic polynomials associated to the filter are derived through renormalization of the load reference impedances. It has been shown that these three conditions can only be satisfied by an ideal filter circuit model separated by a piece of transmission line from the complex load. The key issues in the synthesis approach are to enforce the realizability conditions of a filter network and to match the complex load with a best effort. For this purpose, it is proved that a section of transmission line with an optimal length must be inserted between the filter network and the complex load. The length of the transmission line will be optimally designed in the sense that the designed filter will best match to the complex load over a given frequency range.

Prof. Ke-Li Wu：Ke-Li Wu received the B.S. and M.Eng. degrees from the Nanjing University of Science and Technology, Nanjing, China, in 1982 and 1985, respectively, and the Ph.D. degree from Laval University, Quebec, QC, Canada, in 1989. From 1989 to 1993, he was with the Communications Research Laboratory, McMaster University, as a Research Engineer and a Group Manager. In March 1993, he joined the Corporate R&D Division, COM DEV International, where he was a Principal Member of Technical Staff. Since October 1999, he has been with The Chinese University of Hong Kong, Hong Kong, where he is a Professor and the Director of the Radiaofrequency Radiation Research Laboratory (R3L).
   He has authored or coauthored numerous publications in the areas of EM modeling and microwave and antenna engineering. His current research interests include PEEC and DPEC electromagnetic modeling of high speed circuits, RF and microwave passive circuits and systems, synthesis theory and practices of microwave filters, antennas for wireless terminals, LTCC-based multichip modules (MCMs), and RF identification (RFID) technologies. Dr. Wu is a Fellow of IEEE and a member of IEEE MTT-8 subcommittee (Filters and Passive Components). He serves as a TPC member for many international conferences including IMS. He was an Associate Editor of IEEE Transactions on MTT from 2006 to 2009. He was the recipient of the 1998 COM DEV Achievement Award for the development of exact EM design software of microwave filters and multiplexers.