Reconfigurable Patch Antenna for Polarization Diversity

A novel design of patch antennas with polarization diversity is proposed and experimentally studied in this letter. A pair of L-type slits is embedded into the edge of square patch and the shape of the slit is changed according to on- or off-state of PIN diode. Therefore, the proposed patch antenna has different polarizations. The novel structure we describe here enables the optimization of the input match for both polarizations. From the measured result, low cross-polarization levels in the linear state and good axial ratios in the circular state are observed.