A zero beam-squinting leaky-wave antenna using NRI-TL metamaterials

A planar zero beam-squinting leaky-wave antenna is proposed at 5 GHz, consisting of a periodic arrangement of negative-refractive-index transmission-line (NRI-TL) metamaterial unit cells. The antenna is centre-fed through a 50-ohm transmission line, and the two constituent parallel branches of the antenna each consist of twelve 100-ohm NRI-TL metamaterial unit cells. Each branch of the antenna radiates a beam in opposite directions, and the combination of the two beams results in a symmetric broadside beam over a wide zero-scanning bandwidth of 1.2 GHz (24%).