Dual-polarized multi-layer patch antenna with pattern reconfigurable characteristic

A dual-polarized multi-layer patch antenna with ±45° pattern reconfigurable characteristic is presented. The two-port antenna contains two same-size substrate layers, with a common ground between them. A driven patch and two parasitic patches are printed on the top side of the upper layer. Through two H-shaped slots in the ground, the antenna is fed by the feedlines printed on the bottom side of the lower layer. By adjusting the states of switches mounted on the ground, the antenna can switch among one wide-beam mode and three narrow-beam modes in both polarizations. With a small parasitic layer placed over the driven patch, the patterns of the two polarizations achieve good agreement.