Professor George Eleftheriades
The Edward S. Rogers Sr. Dept. of Electrical and Computer Engineering
University of Toronto

Recently there has been renewed interest in artificial materials with electromagnetic properties that cannot be found in nature. Therefore these materials are referred to as "metamaterials" ("meta" means "beyond" in Greek). This lecture addresses metamaterials that can support negative refraction of electromagnetic waves. For example, the feasibility of media that simultaneously exhibit negative permittivity and negative permeability, hence a negative refractive index, has been known since the sixties. However it is only recently that people invented ways to realize them. In such negative-refractive-index (NRI) or "left-handed" metamaterials, waves can be thought of as propagating backwards instead of forwards. When interfaced with conventional dielectric materials, incident waves become focused on a point instead of diverging outwards, thus suggesting the implementation of lenses with flat surfaces.

In this lecture, first the fundamental properties of NRI metamaterials will be reviewed. Subsequently, it will be demonstrated that NRI metamaterials can be synthesized using planar networks of loaded transmission lines (TL). The resulting NRI-TL metamaterials can be easily constructed using embedded capacitors and inductors, and they offer wide operating bandwidths. Recent 3D isotropic NRI-TL metamaterials will also be discussed. Based on this approach, microwave NRI metamaterial lenses that can resolve details beyond the classical diffraction limit will be presented. Moreover, a number of useful antenna and microwave devices, enabled by those or similar negative-refraction TL metamaterials will be demonstrated. Finally, potential realizations of NRI-TL metamaterials at optical frequencies will be briefly discussed. These enabling materials and devices can find applications in diverse areas such as wireless communications, defence, and medical imaging.

George V. Eleftheriades earned his Ph.D. and M.S.E.E. degrees in Electrical Engineering from the University of Michigan, Ann Arbor, in 1993 and 1989 respectively, and a diploma in Electrical Engineering from the National Technical University of Athens, Greece in 1988. In the period 1994-1997 he was with the Swiss Federal Institute of Technology in Lausanne. Presently he is a full Professor and holds the Canada Research Chair/Velma M. Rogers Graham Chair in the Department of Electrical and Computer Engineering at the University of Toronto. Dr. Eleftheriades is the wireless thrust leader of the Emerging Communications Technology Institute (ECTI) at the University of Toronto.

Dr. Eleftheriades received the Ontario Premier's Research Excellence Award in 2001. In 2004 he received an E.W.R. Steacie Fellowship from the Natural Sciences and Engineering Research Council of Canada. Dr. Eleftheriades is a Fellow of the IEEE and serves as a Distinguished Lecturer for the IEEE Antennas and Propagation Society.

His present research interests include negative-refraction metamaterials for microwave and optical applications, antennas and components for wireless communications, novel antenna beam-steering techniques, low-loss Silicon micromachined components, plasmonic nano-structures, and electromagnetic design for high-speed digital circuits.