A compact circularly polarized slotted patch antenna for GNSS applications

A compact circularly polarized (CP) square-ring slotted patch antenna with vias is proposed for global navigation satellite systems (GNSS). Four square-ring-shaped slots are cut symmetrically onto a square patch radiator along its diagonals for wide-angle CP radiation and miniaturization. The antenna size is further reduced by grounding the central patches surrounded by the square-ring-shaped slots. An antenna prototype with an overall size of 60 mm x 60 mm x 5 mm shows a measured 10-dB return loss bandwidth of 90.0 MHz (1.565-1.655 GHz) with a maximum gain of 4.65 dBic. The measured 3-dB axial ratio (AR) bandwidth is 35.0 MHz (1.57-1.605 GHz) with a 3-dB AR beamwidth of more than 140° across the bandwidth.