NIT Strategic Workshop Emerging Technologies for Future Optical and Wireless Networks September 8 & 9, 2003 Negative Refractive Index Metamaterials Using Loaded Transmission Lines and Enabling RF Devices Prof. George V. Eleftheriades Dept. of Electrical and Computer Engineering University of Toronto Abstract. Recently there has been intense research interest in man-made materials with superior electrical properties that cannot be found in nature. For this reason these materials are currently referred to as “metamaterials” (“meta” means “beyond” in Greek). The feasibility of constructing man-made media that simultaneously exhibit negative permittivity and negative permeability, hence a negative refractive index, has been known since the sixties. In negative refractive index (NRI) 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. Materials with such peculiar properties have the potential to significantly change the world of wireless communications, radar, and optical lithography through sub-wavelength resolution. In this presentation it will be demonstrated that NRI metamaterials can be synthesized using planar networks of periodically L-C loaded transmission lines (G.V. Eleftheriades, A.K. Iyer and P.C. Kremer, “Planar negative refractive index media using periodically L-C loaded transmission lines,” IEEE Trans. on Microwave The­ory and Techniques, vol. 50, no. 12, pp. 2702-2712, Dec. 2002). The resulting cellular metamaterial structures are compact, planar and can be easily constructed using lumped capacitors and inductors. Since no resonators are explicitly involved they offer very wide operating bandwidths. Based on this approach, completely planar NRI metamaterial lenses at RF frequencies operating over an octave bandwidth will be presented. Their sub-diffraction imaging characteristics will be discussed along with their related ability to enhance evanescent waves. A number of other metmaterial-enabled RF devices will also be presented including couplers and phase shifters. Biography. 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. He received a diploma (with distinction) 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, where he was engaged in the design of millimetre and sub-millimetre-wave receivers and in the cre­ation of fast CAD tools for planar packaged microwave circuits. In 1997 he joined the Department of Electrical and Computer Engineering at the University of Toronto where he is now an Associate Professor. Dr. Eleftheriades has authored or co-authored more than 80 articles in refereed journals and conference proceedings. He was a co-recipient of the Best Paper Award at the 6th International Symposium on Antennas (JINA), France 1990. More recently, his graduate students won Best Student Paper Awards in the 2000 “Antenna Technology and Applied Electromagnetics” symposium, the 2002 IEEE Intl. Microwave Symposium and the 2002 Intl. Symposium on Antennas and Propagation. Dr. Eleftheriades received the Ontario Premier’s Research Excellence Award in 2001. Currently he is leading a Group of fifteen graduate students in the areas of negative-refractive-index metamaterials, IC antennas and components for broadband wireless communications, novel antenna beam-steering tech­niques, low-loss silicon micromachined components, sub-mm-wave radiometric receivers, and electro­magnetic design for high-speed digital circuits. More info: Prof. Eleftheriades' web site