Dual-Polarized Wideband Fabry–Perot Antenna With Quad-Layer Partially Reflective Surface

A new quad-layer partially reflective surface (PRS) is presented in this letter for dual-polarized Fabry-Perot (FP) cavity antennas with an improved gain bandwidth. Four layers of metallic square rings are printed on each side of two dielectric substrates separated by an air gap of about λ/27 (λ is the wavelength in the open air) at 5.5 GHz. The total profile of the FP cavity is about λ /2. By properly choosing the dimensions of square rings and the distance between the two substrates, the phase of the reflection coefficient of the PRS increases with the operating frequency, demonstrating a broadband property. In order to validate the performance of the proposed PRS, a dual-polarized FP antenna is designed, which has peak realized gains of 14.7 and 15.5 dBi with 1 dB bandwidths of more than 10% for two polarizations. Furthermore, the input reflection coefficients are lower than -15 dB in the 5.05-5.8 GHz band, and the isolation of the dual-polarized modes is more than 30 dB.