IEEE Seminar: Electrically-Small Resonators as the Lego of Electromagnetic Systems

Thursday, November 16, 2017 2:00 pm - 3:00 pm EST (GMT -05:00)

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Abstract:  When Smith, Pendry and others started tinkering with split-ring resonators (SRR) for realizing double negative media, little did we know then that these earlier ground breaking works ushered the beginning of a completely different perspective on designing all types of electromagnetics-based systems. The SRR, or any other resonator that has dimensions much smaller than the wavelength were used as the building blocks for single and double negative media and even near-zero media. While these exotic media enabled cloaking and design of dispersion-controlled media, the applications were largely limited. The concept of a building block, however, might hold the key to a much larger class of designs and applications. Back in the seventeenth century, Huygens conceived the idea of elementary sources as forming the radiated or scattered field. His extraordinary perception of the mechanism of the wave phenomenon preceded the full-fledged development of Maxwell equations by more than 150 years. While Huygens work was an attempt to understand the wave phenomenon through analysis, we pose the question of whether we can extend the concept of building blocks or elementary sources to synthesize electromagnetics based radiating systems. If all things in nature are composed of identical building blocks, can we conceive of a similar construction of electromagnetics systems in general?

In this talk, I will focus on the importance of understanding what is meant by metamaterial, metasurface particles or electrically-small resonators in general. Unlike building blocks used for other physical systems that are not founded on the action-at-a-distance phenomena, the electrically-small resonators, or electromagnetic Legos are more intriguing as their strong coupling needs to be tailored to ensure their desired operation. Several new designs of electromagnetics systems from lenses, to sensors and antennas will be discussed in details covering a broad range of activities conducted in my research group at Waterloo. Focusing on the concept of a building block will naturally reignite strong interest in understanding the fundamental physical phenomenon of radiation and hopefully would lead to asking important questions that were considered of secondary importance in earlier times.

Omar M. Ramahi received the BS degrees in Mathematics and Electrical and Computer Engineering from Oregon State University, Corvallis, OR. He received his M.S. and Ph.D. in Electrical and Computer Engineering from the University of Illinois at Urbana-Champaign. From 1993 to 2000, he worked at Digital Equipment Corporation (presently, HP), where he was a member of the alpha server product development group. In 2000, he joined the faculty of the James Clark School of Engineering at the University of Maryland at College Park as an Assistant Professor and later as a tenured Associate Professor. At Maryland he was also a faculty member of the CALCE Electronic Products and Systems Center. Presently, he is a Professor in the Electrical and Computer Engineering Department. He is a co-author of the book EMI/EMC Computational Modeling Handbook, 2nd Ed. Professor Ramahi has served as a consultant to several companies. Professor Ramahi won the Excellent Paper Award in the 2004 International Symposium on Electromagnetic Compatibility, Sendai, Japan, and the 2010 University of Waterloo Award for Excellence in Graduate Supervision. In 2012, Professor Ramahi was awarded the IEEE Electromagnetic Compatibility Society Technical Achievement Award. Dr. Ramahi is an elected IEEE Fellow. In 2009, he served as a Co-Guest Editor for the Journal of Applied Physics Special Issue on Metamaterials and Photonics. From 2007-2015, he served as an Associate Editor for the IEEE Transactions on Advanced Packaging. From 2010-2012, he served as an IEEE EMC Society Distinguished Lecturer. In 2014, he served as a Guest Editor for the journal Sensors, special issue on Metamaterial-Inspired Sensors. He has authored over 390 journal and conference papers.