Dual-polarized probe-fed patch antenna with highly decoupled ports for WLAN base station

In this paper we present a novel dual-polarized patch antenna using two probe feeds for achieving high port decoupling. By using a thick air-layer substrate, which makes possible a wide impedance bandwidth. The two probe feeds have a short probe pin and a triangular transition patch (F.S. Chang and K.L. Wong, Microwave Opt. Technol. Lett. vol. 30, pp. 341-343, 2001), which makes good impedance matching over a wide frequency range very easy to obtain. In addition, an additional shorted inverted-L patch is added, which is for the purpose of decreasing the excited patch surface currents flowing from the excited port toward the other one, such that great improvement in port decoupling can be obtained. Details of the proposed design are described, and a prototype suitable for the dual-polarized WLAN base-station application at 2.45 GHz band (2400-2485 MHz) is constructed and studied.