Design and study of wideband single feed circularly polarized microstrip antennas

Abstract

The performance of single feed truncated corner circularly polarized microstrip antennas with different substrate thickness is studied by simulation and experiment. It is found that the axial ratio bandwidth could be enhanced considerably when a thicker substrate is used, provided that a U-slot and/or L-probe is used to effect impedance matching. One of the configurations attains an axial ratio bandwidth (< 3 dB) of about 14% within the impedance matching band when the substrate thickness is about 0.2λo.