A Wideband High-Isolated Dual-Polarized Patch Antenna Using Two Different Balun Feedings

In this letter, a dual-polarized patch antenna with low profile and wide bandwidth is presented. The square patch, where a bow-tie slot is etched on, is excited by two different balance-to-un-balance feedings for dual polarization. One of the polarizations is excited by the central-placed transition, which transfers the unbalanced microstripline feed to the balanced slot feed. The other polarization is excited by a differential feed network, which contains two capacitively coupled probe feeds. By adopting the two balanced feedings, high isolation and low cross polarization are achieved. A prototype of the proposed antenna is built and tested. Measured results show that the -10-dB reflection coefficient bandwidth of the two polarizations is about 18.8%, with port isolation less than -28.5 dB.