A planar dual polarization antenna for receiving and transmitting radio signals includes a feeding transmission line layer, a first dielectric layer formed on the feeding transmission line layer, a metal grounding plate, a second dielectric layer formed on the metal grounding plate, and a first patch plate formed on the second dielectric layer with a shape substantially conforming to a cross pattern. A first slot and a second slot of the metal grounding plate are electrically coupled to a first feeding transmission line and a second feeding transmission line of the feeding transmission line layer respectively, to increase bandwidth of the planar dual polarization antenna.