Selected Antenna Applications of Negative-Refractive-Index Transmission-Line (NRI-TL) Metamaterials

Metamaterialls (MM) that exhibit a simultaneously negative electric permittivity ε and magnetic permeability μ and thus a negtive refractive index (NRI), have recently attracted considerable attention inthe electromagnetics community. In this article we present a number of antenna applications using NRI-TL metamaterials. These include broadband phase-shifting lines that can produce either a positive or a negative phase shift while exhibiting a broadband linear phase response, associated series power-distribution networks, broadband baluns and electrically small antennas.