Broad beamwidth circularly polarized microstrip antenna for CNSS band application

A novel circularly polarized (CP) microstrip antenna with broad beamwidth is proposed for compass navigation satellite system (CNSS) application. The multi-layer structure is adopted which consists of two circular substrate layers and an air layer. A circular patch antenna with two stubs is laid on the lower substrate to achieve circularly polarized radiation, which is fed through a coaxial probe. Two parasitic rings are introduced to broaden the half-power beamwidth and AR beamwith, which are laid on the upper and lower layer, respectively. With the two parasitic rings, the proposed antenna exhibits a 3dB beamwidth more than 160°, and a 3dB axial-ratio beamwidth more than 180°.