A Compact Multipath Mitigating Ground Plane for Multiband GNSS Antennas

This paper presents the design of a novel multipath mitigating ground plane for Global Navigation Satellite System (GNSS) antennae. Firstly, the concept of a compact low multipath cross plate reflector ground plane (CPRGP) is presented. In comparison to the choke ring and Electromagnetic Band Gap (EBG) ground planes, the proposed CPRGP has compact size, low mass, wide operational bandwidth and simple configuration. The proposed CPRGP is then integrated with a circularly polarized dual-band GNSS antenna in order to assess the multipath mitigating performance over two frequency bands. Measurement results of the proposed CPRGP with GNSS antenna achieves a front to back ratio (FBR) over 25 dB at L1 (1.575 GHz) and L2 (1.227 GHz) bands and maximum backward cross polarization levels below -23 dB at both bands. Antenna phase centre variation remains less than 2 mm across both L1 and L2 bands. Furthermore, the performance comparison of the proposed CPRGP with the commercially available pinwheel antenna and the shallow corrugated ground plane is presented, showing the advantages of CPRGP for high precision GNSS applications