Date and Time Wed, May 22nd, 2013, 3:00 PM - 4:00 PM
Location Bahen Centre, Room 7180
Host Xiao Sun

Multi-band microwave devices using generalised-negative-refractive-index transmission line

Colan Ryan

Eleftheriades Group, Electromagnetics



Negative-refractive-index transmission lines (NRI-TLs) have found a wide variety of uses in microwave engineering design. With both a forward- and a backward-wave propagation band, these structures can be used, for instance, to reduce overall component size or to create dual-frequency devices. A Generalised-NRI-TL (G-NRI-TL) is an extension of this concept and possesses two pairs of forward- and backward-wave bands, consequently enabling multiple operating frequencies, albeit at the expense of increased circuit complexity.

This talk focuses on applying NRI-TLs and G-NRI-TLs to three fully-printed microwave devices. First, a dual-band circularly-polarised patch antenna is developed using NRI-TL loading. A meander-antenna array for MIMO applications is then presented in which metamaterial components are used to increase both radiation efficiency and bandwidth. Finally, a single-ended all-pass metamaterial lattice network is discussed. This network permits the dual- or quad-band phase characteristics of “standard” metamaterial transmission lines, yet maintains a perfect match to the system impedance and so represents an improvement over the conventional NRI-TL approach.


Colan Ryan received his B.A.Sc. in Electrical Engineering from the University of Ottawa in 2006. After completing his M.A.Sc. thesis at the Royal Military College in collaboration with the Communication Research Centre in Ottawa, he joined the Electromagnetics group at U of T as a Ph. D. student under the supervision of Dr. George Eleftheriades; his graduate research focuses on antenna design and transmission-line metamaterials.