The Marvels of Electromagnetic Band Gap _EBG_ Structures

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					Department of Electronic Engineering                                                             IEEE AP/MTT HK
                                                                                                   Joint Chapter


         The Marvels of Electromagnetic Band Gap (EBG) Structures
                                                Prof Yahya Rahmat-Samii
                                              Department of Electrical Engineering
                                           University of California, Los Angeles, USA

Periodic structures are abundant in nature and they have fascinated artists and scientists alike. When they interact with
electromagnetic waves amazing features result. In particular, characteristics such as frequency stopbands, passbands
and bandgaps could be identified. Surveying the literature, one observes that various terminology have been used
depending on the domain of the applications. These applications are seen in filter designs, gratings, frequency
selective surfaces (FSS), photonic crystals and bandgaps (PBG), etc. We classify them under the broad terminology of
“Electromagnetic Band Gap (EBG)” structures. Generally speaking, EBG structures are 3-D periodic objects that
prevent the propagation of the electromagnetic waves in a specified band of frequency for all angles of arrival and for
all polarization states. However, in practice, it is very hard to obtain such complete bandgap structures and partial
bandgaps are achieved. For example, filters typically cover the scalar situation and single angle of arrival. FSS
typically cover limited angles of arrival and respond differently to polarization states. PBG typically cover in-plane
angles of arrival and also sensitive to polarization states. FSS terminology has been widely used in the microwave
community while PBG terminology has been widely applied in the optical community. The aim of this presentation
is to provide the electromagnetics/optical device and antenna community with an up to date body of knowledge on
the applications of EBG structures. Specifically, this presentation will focus on: (a) engineering introduction to
EBG and the unification of the terminology, (b) advanced computational and optimization techniques applicable to
EBG, (c) FSS designs, (d) PBG in nano-cavities, (e) optical waveguides for bending the light, (f) smart surfaces
for communication antenna applications, (g) surfaces with perfectly magnetic conducting properties (PMC), (h)
creation of meta-materials with negative permittivity and negative permeability, and (i) surfaces with reduced edge
diffraction effects. Representative numerical and measurement results will be presented. Future applications of
EBG structures will be highlighted.
Yahya Rahmat-Samii is the Chairman and a Professor of Electrical Engineering at the University of California,
Los Angeles (UCLA). Before joining UCLA, he was a Senior Research Scientist at NASA's Jet Propulsion
Laboratory/California Institute of Technology. Dr. Rahmat-Samii was the 1995 President of IEEE Antennas and
Propagation Society and was appointed an IEEE Distinguished Lecturer and presented lectures internationally. Dr.
Rahmat-Samii was elected as a Fellow of IEEE in 1985 and a Fellow of IAE in 1986. He also served as the Vice
President of AMTA. Dr. Rahmat-Samii was the 1984 recipient of the prestigious Henry Booker Award of
USNC/URSI. Dr. Rahmat-Samii has authored and co-authored over 500 technical journal articles and conference
papers and has written 17 book chapters and two books. His research contributions cover diverse areas of
electromagnetics, antennas, satellite and personal communications, advanced material, modern measurement
techniques, numerical and optimization techniques, etc (visit For his contributions, Dr.
Rahmat-Samii has received numerous awards, including the 1992 and 1995 Wheeler Best Application Prize Paper
Award for his papers published in the IEEE Antennas and Propagation Transactions, 1999 University of Illinois
ECE Distinguished Alumni Award, IEEE Third Millennium Medal, and AMTA’2000 Distinguished Achievement
Award. In 2001, he received the Honorary Doctorate in Physics from the University of Santiago De Compostela,
Spain and in the same year he was elected as the Foreign Member of the Royal Flemish Academy of Belgium for
Science and the Arts.
                                          Date:     January 3, 2003 (Friday)
                                          Time:     10:30 am – 12:00 nn
                                          Venue:    G5216 (Please take lift no. 7 to 5 floor)
                                                    City University of Hong Kong

                                                      ALL ARE WELCOME
Language: English

Enquiry: Dr K W Leung, Department of Electronic Engineering, CityU
Tel: 2788 9382 Fax: 2788 7791 Email:

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