Planar antenna design for omnidirectional conical radiation through cylindrical leaky waves
An annular periodic leaky-wave antenna (LWA) fed by a simple azimuth-symmetric source is designed to generate a high-gain omnidirectional conical beam pattern which scans with frequency over a wide angular range. The proposed structure is defined by a finite metallic radial strip grating printed on a grounded dielectric slab which supports an n = 0 cylindrical leaky wave (CLW) mode. The distinctive features of CLWs supported by such a truncated structure are also highlighted and discussed.