Frequency‐Independent Beam Scanning Leaky‐Wave Antennas

This chapter introduces four types of advanced reconfigurable leaky‐wave antenna (LWA) structures for fixed‐frequency beam scanning, i.e., a reconfigurable Fabry–Perot LWA, a period‐reconfigurable substrate‐integrated‐waveguide LWA, a reconfigurable composite right‐/left‐handed LWA, and a uniplanar two‐dimensional multi‐beam LWA suited for millimeter‐wave operations. These antenna configurations and their operating mechanisms and performance are described. A way to produce a full‐range scanning LWA is through the introduction of metamaterial constructs, i.e., artificial materials with exotic properties that can be tailored to a given application. The two‐dimensional multi‐beam antenna presented divides the problem of generating 2‐D multi‐beams into two independent, one‐dimensional beamforming pieces. This topology makes it possible to have a flat uniplanar structure. Some future directions of research in reconfigurable LWAs are discussed to conclude the chapter.