A Broadband Circular Polarization Antenna Applied For Base-Station

This paper studies the broadband circularly polarized antenna used in micro base stations. The antenna consists of a pair of rectangular loops. The ring patch is used to form circular polarization, and a pair of open resonant ring parasitic elements are loaded between the two rectangular rings to increase the bandwidth. By introducing balun feed to increase bandwidth, good impedance matching can be obtained. Add a metal reflector at the bottom of the antenna to form directional radiation. The antenna was printed on the Rogers RO4003 substrate, and the results showed that the -10dB return loss bandwidth was 43.4% (1.86-2.89GHz), and the -3dB axial ratio bandwidth was 41% (1.9-3GHz). The gain of the antenna in the frequency band is greater than 9dBi.