Lead Invited Talk: Antenna Applications of Negative-Refractive-Index Transmission-Line Metamaterials

Metamaterials are artificial structures that have been engineered to exhibit electromagnetic properties that are not usually found in natural media. Metamaterials that exhibit a simultaneously negative electric permittivity ε and magnetic permeability μ, and thus a negative refractive index (NRI), have recently attracted considerable attention in the microwave community [1],[2]. This has been motivated by the potential to create new microwave devices that exhibit superior qualities compared to their conventional counterparts [3]-[5]. A useful method of implementing planar metamaterials is based on reactively loaded transmission lines (TL). Transmission line NRI media consist of a network of printed transmission lines periodically loaded with lumped-element series capacitors (Co) and shunt inductors (Lo) in a dual-TL (high-pass) configuration [3]-[14]. The planar nature of the TL-based metamaterial (MM) structures renders them well suited for the realization of planar microwave antennas and circuits [3]-[14]. Recent review articles on the characteristics and potential applications of metamaterials can be found in [13]-[15].