报告题目：Nature of Antenna Radiation Revealed by Full-wave Micro-Modeling Circuit
报 告 人：Prof. Ke-Li Wu 吴克利教授
报告地点：文昌科创楼 3 号 405 室
Since Guglielmo Marconi sent the first ever wireless communication over the Bristol Channel with antennas in 1897, the antenna has become an indispensable tool in the daily lives of human beings for transmitting and receiving signals through radio waves. Since then, efforts to elucidate the fundamental principles of antennas have never been ceased. Among these works, finding a physically sensible circuit model of an antenna that could represent the essence of the antenna has long constituted a challenge.
This seminar will be started by reviewing the theory of generalized partial element equivalent circuit (G-PEEC) model. The G-PEEC model is the only full-wave and passive circuit model for general EM problem. Its real valued self- and mutual-capacitance and inductance are associated to the charge and current meshes, respectively, designating the self-and mutual-radiative resistance for radiation effect. By recursively applying the circuit transformation to the “insignificant nodes”in G-PEEC, and stipulating the stopping criteria in both broad and narrow senses, a concise, physically meaningful, full-wave and passive circuit model, namely micro-modeling circuit (MMC), can be systematically generated.
In the second part of this talk, the nature of antenna radiation is revealed with the full-wave MMC. Specializing the Poynting Theorem, the total radiated power is found to the lumped sum of the partial dissipated power, positive and negative, on the discrete self- and mutual- radiative resistances. A new perspective of radiation efficiency is given in terms of powers governed by mutual radiative resistance and self-radiative resistance. The holographic radiation diagram that displays the association of the partial radiated power with the antenna geometry is introduced. It will be shown that, for a given antenna configuration, mutual radiation resistances that are associated with interactions among antenna segments contribute to positive and negative radiated power. In contrast with classic antenna theories, which only predict the bound of antenna bandwidth vs. radiation efficiency in a broad sense, it will be shown in this talk that the radiation efficiency is determined by the partial radiated power contributed by the mutual resistive coupling. Examples will demonstrate how to design an antenna of high radiation efficiency with the guidance of the holographic radiation diagram. The MMC is also a useful tool for the EMC and other problems, in which EM radiation is concerned.
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, 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 (now Honeywell Aerospace), Cambridge, ON Canada, 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 top tier journals in the areas of EM modeling and microwave passive components, microwave filter and antenna engineering. His current research interests include electromagnetic modeling of high speed circuits, RF and microwave passive circuits and systems, robot automatic tuning of microwave filters, MIMO array antennas, and IoT technologies and applications.
Prof. Wu is a Fellow of IEEE, a member of IEEE MTT-8 subcommittee (Filters and Passive Components) and also serves as a TPC member for many prestigious international conferences including International Microwave Symposium. 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, and Asia Pacific Microwave Conference Prize both in 2008 and 2012.