A Broadband Dual-Circularly Polarized Fixed-Beam Leaky-Wave Antenna for Point-to-Point and Satellite Communication Applications

In this paper, a broadband dual-circularly polarized (CP) fixed-beam leaky-wave antenna (LWA) is designed. The planar equiangular spiral antennas are introduced into the LWA design and used as radiating elements to realize dual CP radiation. Two ridge gap waveguides (RGWs) arranged side-by-side are used as the basic transmission structures. Metal slots are periodically etched on the RGWs, which couple the energy transmitted in RGWs up to corresponding microstrip branches, and then transmits to the radiating elements. The fixed beam at broadside is realized by phase compensation of adjacent microstrip branches. The designed antenna prototype is simulated, manufactured and measured. From 24 to 39 GHz (48.8%), the LWA can achieve stable broadside dual CP radiation and the measured peak gain is 14.6 dBic. The antenna realizes the characteristics of both fixed beam and dual CP radiation in a wide bandwidth, and shows great potential in point-to-point and satellite communication applications.