Quad-Band Probe-Fed Stacked Annular Patch Antenna for GNSS Applications

A novel probe-fed stacked annular patch antenna is proposed for Global Navigation Satellite System (GNSS) applications. The antenna has been designed to operate at the satellite navigation frequency bands including GPS, GLONASS, BDS-1, and BDS-2. In the design, four annular patches are stacked to achieve multiband operation and compactness. Quadrature phase feed network comprising four 90 degrees stripline baluns is employed to ensure circularly polarized (CP) radiation. Another key feature of our design is the stepped-radius shorting pillar to reduce the well-known inductance due to longer feeding probes. The final antenna exhibits good impedance matching, broad pattern coverage, and pure CP performance at all designed bands. Details of design considerations and experimental results are presented and discussed.