题目：Designs of Diversity Dielectric Resonator Antennas
报告人：Kwok Wa (Ben) Leung （梁国华）, IEEE Fellow
In modern wireless communication systems, diversity techniques have been widely used to mitigate the multipath problem and increase the system capacity. As compared with the multi-antenna diversity system, a single-element diversity antenna is more attractive because its size is more compact. In this talk, two different diversity dielectric resonator antennas (DRA) will be presented. The DRA is a promising antenna due to a number of merits such as its compact structure, high efficiency, and ease of excitation. The talk will first discuss the design of a two-port circularly polarized(CP) pattern-diversity DRA. Port 1 of the diversity DRA makes use of the omnidirectional TM01δ mode to obtain an omnidirectional radiation pattern, whereas Port 2 employs the HEM12d+1 DRAmode to obtain a broadside radiation pattern. Forthe second diversity CP DRA,the TM01δ and TE011+δ modes that are orthogonal to each other are used.Omnidirectional CP fields can be obtained when the (orthogonal) fields of the TM01δ and TE011+δ modes are equal in amplitude but in phase quadrature. The phase differences of +90o and -90oare obtained in Ports 1 and 2 to generate the right- and left-hand CP fields, respectively.Comparisons between theory and experiment will be given for both designs.
Kwok Wa (Ben) Leung was born in Hong Kong. He received the B.Sc. degree in electronics and the Ph.D. degree in electronics engineering from the Chinese University of Hong Kong, Hong Kong, in 1990 and 1993, respectively. In 1994, he joined the Department of Electronic Engineering, City University of Hong Kong (CityU) and is currently a Chair Professor and the Associate Head. From January to June, 2006, he was a Visiting Professor at the Department of Electrical Engineering, The Pennsylvania State University, State College, PA, USA. His research interests include antenna designs and EM theory. Prof. Leung received the International Union of Radio Science (USRI) Young Scientists Awards in Japan and Russia, in 1993 and 1995, respectively. He received the CityU Research Excellence Award 2013 and Departmental Outstanding Teacher Awards in 2005, 2010, and 2011. He also received the highly prestigious First Class Award (Natural Science) in the 2016 Higher Education Outstanding Scientific Research Output Awards (Science and Technology) of the Ministry of Education, China. His students received the 2015 iWEM Student Best Paper Award, 2015 IEEE AP-S Eugene F. Knott Memorial Pre-Doctoral Research Award, and 2014 IEEE MTT-S Undergraduate/Pre-graduate Scholarship. He was Chair of the IEEE AP/MTT Hong Kong Joint Chapter for 2006 and 2007. He was the Technical Program Chair, 2008 Asia-Pacific Microwave Conference, Hong Kong, and the Technical Program Co-Chair, 2006 IEEE TENCON, Hong Kong. He was a Guest Editor of IET Microwaves, Antennas and Propagation. He served as Associate Editor for the IEEE Antennas and Wireless Propagation Letters. He was also an Associate Editor for the IEEE Transactions on Antennas and Propagation and received Transactions Commendation Certificates twice in 2009 and 2010 for his exceptional performance. He was the Editor-in-Chief of the Transactions from 2013 to 2016, being the first Chinese and also the first appointed from Asia since the journal was founded in 1952. He was a Distinguished Lecturer of the IEEE Antennas and Propagation Society. He is currently a member of the AP-S Distinguished Lecturer Program Committee. He is a Fellow of IEEE.