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.

I. Introduction

In a spaceborne system, a wideband circular polarization feed irradiator is necessary to build a reflector antenna for specific coverage on the ground, realizing ground target wave signal acquisition and source location. For the application background of communication satellite, the feed antenna should have the following characteristics: working bandwidth at 0.2GHz-0.3GHz to meet the requirement of circular polarization; high gain to ensure the reflector antenna of capturing enough energy; the radiation pattern with frequency change being symmetrical with a stable beam width; low profile, small volume, light weight, easy to install. Based on the research background this paper presents the design of low profile wideband circularly polarized antenna.