Miniaturization of S-band circularly polarized microstrip antenna

Abstract

A S-band miniaturized circularly polarized microstrip antenna is designed and fabricated. The curved current technique is utilized, and the effective path length of current is increased by loading the U-shaped slot on the radiating patch. Thus the antenna resonant frequency can be tuned and the antenna can be significantly miniaturized. The experimental samples of the antenna are fabricated and tested. The measured results show that the two resonant frequencies of the miniaturized S-band circularly polarized microstrip antenna are 2.17GHz and 2.25GHz, with an impedance bandwidth (S11 < 10 dB) of 152 MHz (from 2.132 GHz to 2.284 GHz). The measured gain is about 0dB. The measured results are basically consistent with the simulation results.