Dual polarization antenna with high isolation

Abstract

A dual-polarized antenna with high isolation is disclosed. A first differential signal feeding unit extends from a first input port toward one side of a patch radiator through a dielectric substrate, and is branched into a balun structure to provide first and second feeding probes for differentially feeding vertically polarized signals to opposite first and second portions of the patch radiator. A second differential signal feeding unit extends from a second input port toward another side of the patch radiator through the dielectric substrate, and is branched into the balun structure to provide third and fourth feeding probes for differentially feeding horizontally polarized signals to opposite third and fourth portions of the patch radiator. When feeding the vertically polarized signals through the first and second feeding probes, a virtual ground region in which there is little electric field is formed in the center portion of the patch radiator. The cross-sectional polarization components of the third and fourth probes are also greatly reduced, so that they hardly exist. A soft surface structure surrounding the patch radiator and the first to fourth probes can improve the radiation pattern deterioration caused by diffraction of surface waves.