A Low Profile Broadband Circularly Polarized Microstrip Antenna

This paper introduces the design and simulation of a broadband circularly polarized microstrip patch antenna. The antenna consists of a circular patch, an air layer and four Lprobes. The distance between the patch and ground is only 0.058 times of the free space wavelength at 0.25GHz, achieving low profile characteristic. The HFSS simulation results show that VSWR is better than 2 in 42.2% bandwidth, the axial ratio is less than 1.5dB, and the antenna peak gain is 10.6dBi.