Circularly polarized microstrip antenna with an airgap for multi-GNSS applications

We present a new circularly polarized microstrip antenna with an airgap for multiple Global Navigation Satellite System (multi-GNSS) receivers. The airgap structure substantially increases antenna gain and bandwidth. We examined the antenna properties by simulation and measurement. The measured results show the -10 dB bandwidth of 4.9% and the maximum antenna gain above 7.0 dBi over the whole multi-GNSS frequency band. We performed an experiment on receiving satellite signals by a prototype antenna, and confirmed that good CNR values can be obtained over wide elevation angle range of 20 to 90 degree.