Wideband Proximity-Fed Low Profile Circularly Polarized Patch Antenna

This paper presents a low profile, circularly polarized patch antenna using proximity coupled feeds. A wide bandwidth was achieved by exciting the patch antenna with four proximity coupled feeds from a wideband phase shifting network. The simulated 10 dB vertical bar S-11 vertical bar bandwidth was from 1480 MHz to 2730 MHz (58.4%) and the simulated 3 dB axial ratio bandwidth was from 1650 MHz to 2820 MHz (52.4%). The peak gain of the antenna was simulated to be 4.4 dBi at 2000 MHz in the broadside direction. This was achieved while maintaining a very low profile of 0.05 lambda, where lambda is the wavelength corresponding to the lowest operating frequency. The overall antenna dimensions were 75.0 mm x 75.0 mm x 9.2 mm.