Fixed-frequency beam-steerable leaky-wave antenna operating over a wide band

In this paper, a Half-Mode Substrate Integrated Waveguide (HMSIW) with interdigital slots mounted on its surface is used to explore fixed-frequency beam-steerable characteristic of Composite Right/Left Handed (CRLH) antenna based on HMSIW structure. By combining varactors and the PIN diodes with the antenna structure, fixed-frequency beam-steering radiation pattern can be realized. Main goal of our work is to realize a wide range of beam-steering angle at fixed frequency. In addition, because of the backward-to-forward frequency scanning ability of CRLH structure, we also focused on realizing fixed-frequency beam-steerable ability over a wide band. Moreover, the antenna is designed to be +45° polarized, so there is a potential that the antenna can be circular polarized if combined with the symmetric −45° antenna.