Single-Fed Dual-Band Circularly Polarized Patch Antenna With Wide 3-dB Axial Ratio Beamwidth for CNSS Applications

This paper presents a dual-band circularly polarized (CP) antenna with wide 3-dB axial ratio (AR) beamwidth for compass navigation satellite system (CNSS) applications. The antenna is designed to be a double-layer structure and fed through a single coaxial probe. Two patches stacked together with truncated corners and symmetry L-shaped stubs are used to achieve two operating frequency bands, i.e., B1 (1.561 GHz) and B2 (1.207 GHz), for CNSS. In particular, a circular ground plane with four curved slots is adopted to achieve a symmetrical radiation pattern and a wide 3-dB AR beamwidth. At 1.561 GHz, the peak gain of the proposed antenna is 6.4 dBi, and the 3-dB AR beamwidths of 214°and 200°in the xz- and yz-planes are obtained, respectively. At 1.207 GHz, the proposed antenna has a maximum gain of 6.0 dBi, and the 3-dB AR beamwidths of 221°and 202°in the xz- and yz-planes.