A Corner-Fed Microstrip Circular Antenna with Switchable Polarization

In this paper, a design for a novel microstrip antenna with circular polarization diversity is proposed and experimentally investigated. This antenna is excited by a microstrip line, which is located at the corner of a circular patch. The polarization state can be switched electrically by setting a diode to on or off. The novel structure we describe here enables the optimization of the input match for both polarizations. From the measured result, good axial ratios are observed at the operating frequencies.