A printed ‘bull-eye’ leaky-wave antenna fed by a non-directive surface-wave launcher

A planar `bull-eye' antenna design that utilizes surface-waves (SWs) for leaky-wave (LW) excitation is investigated for millimeter-wave frequencies of operation. Specifically, a planar non-directive surface-wave launcher (SWL) is employed as the antenna feed, generating bidirectional SW field distributions on a grounded dielectric slab (GDS). By the addition of annular metallic strip gratings, LWs can be excited on the planar guiding surface, defining the practical 2-D leaky-wave antenna (LWA).