A novel microstrip patch antenna with both frequency and circular polarization diversities is presented. The proposed antenna consists of two parts, a patch with two orthogonal slots on the upper substrate and a3 d B hybrid coupler fed structure which printed on the lower substrate. Two groups of diodes placed across the orthogonal slots are utilized to achieve frequency reconfiguration. Another two diodes, placed between the input port of the antenna and the 3d B hybrid coupler, are utilized to switch between Left-hand circular polarization(LHCP)and Right-hand circular polarization(RHCP). Full wave simulation is used for the antenna analysis, and a prototype of the antenna with an integrated Direct current(DC) biasing circuit has been fabricated and measured. The results verify the reconfigurable characteristics of the antenna and demonstrate a good candidate for wireless communication applications. A novel microstrip patch antenna with both frequency and circular polarization diversities is presented. The proposed antenna consists of two parts, a patch with two orthogonal slots on the upper substrate and a3 d B hybrid coupler fed structure which printed on the lower substrate. Two groups of diodes placed across the orthogonal slots are utilized to achieve frequency reconfiguration. Another two diodes, placed between the input port of the antenna and 3d 3d hybrids, are utilized to switch between the left-hand circular polarization (LHCP) and the right-hand circular polarization (RHCP). Full wave simulation is used for the antenna analysis, and a prototype of the antenna with an integrated Direct current (DC) biasing circuit has been fabricated and measured. The results verify the reconfigurable characteristics of the antenna and demonstrate a good candidate for wireless communication applications.