UWB Antennas for Wireless Communication and Detection Applications

Prof. Ahmed Kishki

(Ahmed Kishki, Concordia University, Montreal, Canada)

Abstract

Ultra-wide band (UWB) wireless communication occupies a bandwidth from 3.1 to 10.6 GHz, referred to as UWB band, to achieve high data rate over a short distance. Two competing schemes, namely multiband orthogonal frequency division multiplexing (MB-OFDM) and direct sequence ultra wide band (DS-UWB), were proposed to make use of the allocated bandwidth. Ideally, a transmitting/receiving UWB antenna pair comprising a communication channel should operate as a band-pass filter covering the UWB band and have a flat magnitude response and a linear phase response with frequency. It requires an UWB antenna well matched, with frequency independent phase center, and linearly increasing gain with frequency over the entire UWB band.
An omnidirectional UWB antenna is especially attractive to wireless communications at either base station or terminal side. For an omnidirectional UWB antenna, besides the aforementioned three requirements, its radiation performances over the UWB band should also be independent of the azimuth angle. A good impedance matching over the UWB band is not difficult, and many types of antenna can achieve that. Frequency independent phase center is achievable for most antennas except for those with multi-resonant structure spatially separated. But, after the first three requirements are met, a wideband omnidirectional radiation is still challenging for UWB antenna design. Omnidirectional UWB antennas with a non-planar conducting structure as well as DRA are presented for an UWB access point.
Another recently addressed problem is the interference problem with the WLAN bands. To prevent interference problems due to existing nearby communication systems within an Ultra-wideband operating frequency, the significance of an efficient band notched design is increased. Two novel antennas are presented. One antenna is designed for one band-notch. The second antenna is designed for dual band-notches.
Several UWB antennas with unidirectional patterns are presented for detection applications. Dielectric resonator is used to tremendously shrink an UWB antenna’s size to be used as a sensor for breast cancer detection and microwave imaging. Another 3D conducting self-grounded Bow-Tie sensor is presented. The application of such a DR UWB antenna for thro-wall radar detection is also investigated showing better performance as compared to the Vivaldi antenna.

Biography of Dr. Ahmed A. Kishk :

http://scholar.google.ca/citations
Ahmed A. Kishk is a Professor and Canada Reserch Chair in Advanced Antenna System at Concordia University. He is a distinguish lecturer for the Antennas and Propagation Society (2013-2015). He is now an Editor of Antennas & Propagation Magazine. He was an Editor-in-Chief of the ACES Journal from 1998 to 2001. He was the chair of Physics and Engineering division of the Mississippi Academy of Science (2001-2002). He is an AP AdCom member (2013-2015).
His research interest includes the areas of Dielectric resonator antennas, microstrip antennas, small antennas, microwave sensors, RFID antennas, Multi-function antennas, microwave circuits, EBG, artificial magnetic conductors, and phased array antennas. He has published over 240-refereed Journal articles and 380 conference papers. He is a coauthor of four books and several book chapters and editor of three books. He offered several short courses in international conferences.
Dr. Kishk received the 1995 and 2006 outstanding paper awards for papers published in the Applied Computational Electromagnetic Society Journal. He received the 1997 Outstanding Engineering Educator Award from Memphis section of the IEEE. He received the Outstanding Engineering Faculty Member of the Year on 1998 and 2009, Faculty research award for outstanding performance in research on 2001 and 2005. He received the Award of Distinguished Technical Communication for the entry of IEEE Antennas and Propagation Magazine, 2001. He also received The Valued Contribution Award for outstanding Invited Presentation, “EM Modeling of Surfaces with STOP or GO Characteristics – Artificial Magnetic Conductors and Soft and Hard Surfaces” from the Applied Computational Electromagnetic Society. He received the Microwave Theory and Techniques Society Microwave Prize 2004. He received 2013 Chen-To Tai Distinguished Educator Award of the IEEE Antennas and Propagation Society. In recognition “For contributions and continuous improvements to teaching and research to prepare students for future careers in antennas and microwave circuits, Dr. Kishk is a Fellow of IEEE since 1998, Fellow of Electromagnetic Academy, and Fellow of the Applied Computational Electromagnetic Society (ACES). He is a member of several Technical Societies.