A dual polarized UWB slot antenna with kite shaped slot for high isolation

In this paper, the design of a two port antenna for ultra wideband applications is presented. The radiating element in the antenna is an L-shaped slot which is excited using two microstrip feed lines for generating the orthogonal polarizations. The slot and the feed lines have stepped profiles for achieving wideband impedance matching. The decoupling between the ports is provided by means of three different structures. First, a slant metallic strip is attached at a corner inside the L-shape slot, next, a trident shaped slot is etched below the L-shape slot near its corner and finally, a kite shaped slot is placed in the center. The impedance bandwidth achieved with the antenna is from 3 GHz to 11.6 GHz while the isolation is better than 20 dB from 3.8 GHz onwards. The dual polarized nature of the antenna is shown from the aperture electric field distribution and the radiation patterns. The peak gain of the antenna varies from 4 to 6 dBi over the band. The antenna is expected to be useful for dual polarization applications in radar, imaging and high speed wireless communication.