Abstract:
High-gain antennas are useful for modern wireless communication systems. In this talk, two novel high-gain open-horn antennas integrated with metal lenses are presented.
The first design is a compact open-horn antenna for point-to-point applications. It incorporates a spatial power divider and an H-plane lens composed of sub-channels that satisfy the equal-path-length condition, enabling wideband and high-gain performance. The magnitude and phase distributions are independently controlled by different antenna sections to achieve a uniform E-field at the aperture. This antenna demonstrates a gain improvement of approximately 6 dB over a conventional horn. To reduce sidelobe levels, an improved version is developed using a tapered E-field magnitude distribution at the lens input. Both the original and improved designs were fabricated and measured. The improved version achieves a sidelobe level reduction from –9 dB to –15 dB. For both designs, the measured –10 dB impedance bandwidth and 3 dB gain bandwidth exceed 46% (11.5–18 GHz).
The second design is a wideband biconical antenna integrated with a metal lens for omnidirectional applications. It offers full azimuthal coverage, which is good for remote area communications and point-to-multipoint systems such as portable base stations and wireless LANs. At millimeter-wave frequencies, high gain is crucial to compensate for path loss. To enhance gain, the biconical antenna is loaded with an annular metal lens comprising rotationally symmetric plates, producing a quasi-uniform E-field. A Ka-band, vertically polarized prototype was fabricated and tested. It achieved –10 dB impedance and 3 dB gain bandwidths of 43.9% (25.6–40.0 GHz), with a measured peak gain of 9.2 dBi, approximately 4 dB higher than the gain of a conventional biconical antenna.
For both designs, excellent agreement was observed between simulated and measured results. Detailed results and design insights will be presented in the talk.
Biography:
Prof. LEUNG, Kwok Wa received his B.Sc. degree in Electronics and Ph.D. degree in Electronic Engineering from the Chinese University of Hong Kong in 1990 and 1993, respectively. In 1994, he joined the Department of Electrical Engineering at City University of Hong Kong, where he is currently a Chair Professor. He was the Associate Head of the Department and Associate Dean (Research) of College of Engineering. In 2006, he was a Visiting Professor in the Department of Electrical Engineering, The Pennsylvania State University, USA.
Professor Leung was the Chair of the IEEE AP/MTT Hong Kong Joint Chapter for the years of 2006 and 2007. He was a General Chair of 2022 IEEE Conference on Antenna Measurements and Applications, Guangzhou, the Technical Program Chair of 2008 Asia-Pacific Microwave Conference, Hong Kong, and the Technical Program Co-Chair of 2006 IEEE TENCON, Hong Kong. He was an Editor for HKIE Transactions and a Guest Editor of IET Microwaves, Antennas and Propagation. He was an Associate Editor for the IEEE Antennas and Wireless Propagation Letters and IEEE Transactions on Antennas and Propagation (TAP). He was selected as outstanding Associate Editor of the TAP twice in 2009 and 2010. From 2013 to 2016, Prof. Leung was appointed as the Editor-in-Chief of the TAP.
Prof. Leung received the USRI Young Scientists Awards in Japan and Russia in 1993 and 1995, respectively. He received the Departmental Outstanding Teacher Awards in 2005, 2010, and 2011. He also received the CityU Research Excellence Award 2013. He was a Distinguished Lecturer of the IEEE Antennas and Propagation Society from 2012 to 2014. He is the leading recipient of the prestigious First Class Award (Natural Science) of the 2016 Higher Education Outstanding Scientific Research Output Awards, the Ministry of Education, China. He was selected as an awardee of the Distinguished Alumni Awards for 2021, Department of Electronic Engineering, The Chinese University of Hong Kong. His students received the 2015 IEEE AP-S Eugene F. Knott Memorial Pre-Doctoral Research Award and best paper awards in international/regional conferences. He is a Fellow of IEEE.
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