Novel single-fed broadband circularly polarized antenna for GNSS applications

This letter presents the design of a broadband microstrip CP antenna using single-fed technique. The feeding network is integrated within the coupling feed patch to simplify the structure. The proposed antenna is designed for Global Navigation satellite System (GNSS) operating at 1575.42 +/- 10.23 MHz (GPS: L1 band), 1559 approximate to 1592 MHz (Galileo: E2-L1-E1 band), 1602 +/- 5.625 MHz (GLONASS: L1 band) and 1559.052 approximate to 1591.788 MHz & 1610 approximate to 1626.5 MHz (BeiDou Navigation Satellite System B1 and L band). Another advantage of this antenna is the much wider bandwidth in both VSWR and 3 dB axial-ratio compared with traditional single-fed CP antennas. Details of design, simulated and experimental results of this CP antenna are presented and discussed. The measured results confirm the validity of this design which meet the requirement of GNSS applications.