This article presents a dual‐band/dual‐polarized microstrip patch antenna.For a dual‐band retrodirective array system, the dual‐band/dual‐polarized microstrip patch antenna operating at 11 and 12.2 GHz is designed and tested. The antenna consists of one rectangular microstrip patch and a square ring outside of the patch. Two different feeding locations are used for vertical and horizontal polarizations. The vertical polarization is used for a receiving mode and the horizontal polarization for a transmitting mode. The antenna shows a measured gain of 5.2 and 6.8 dBi at 10.9 and 12.2 GHz. The isolation between the two feeding ports is measured to be greater than 15 dB at each center frequency. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:2781–2784, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27217