Single-fed dual-band dual-polarized U-slot patch antenna

A dual-band dual-polarized patch antenna is proposed for WiMax and WLAN systems. Impedance bandwidths of 7.5% and 9.6% can be achieved at 3.6 GHz and 5.2 GHz, respectively. The asymmetrical U-slot has been used to generate the orthogonal modes for circular polarization at 3.6 GHz with a 3dB axial ratio bandwidth of 0.7%, and the linear polarization is obtained by cutting a symmetrical U-slot on the patch. Higher gains at both CP and LP bands are obtained simultaneously. The peak gains in lower and higher bands are 8.5 dBic and 8.6 dBi, respectively. The simulated results of the antenna have been presented and discussed.