AoA and source polarization estimation with circularly polarized multibeam antenna using MUSIC algorithm

The angle-of-arrival estimation algorithm MUSIC using a multibeam antenna was investigated. The antenna is composed of four circularly polarized antenna elements and a beam-forming network, which provides a switchable set of radiation patterns with distinct main lobe directions. Circularly polarized lobes are not affected from random source inclinations in terms of polarization losses. But they have a limited axial ratio beamwidth, being a limitation for direction finding algorithm based on phase difference. This limitation is illustrated and utilizing the MUSIC algorithm. Compensation of the effect of source inclination on the direction of arrival estimation with a multibeam antenna is presented.