Simple broadband dual-polarized printed antenna

A novel broadband dual-polarized microstrip antenna suitable for array applications is presented. It uses an aperture-coupled feed for one polarization, while a microstrip-line feed with slotted ground plane is used for the other polarization. The antenna can make good use of the space on both sides of the ground plane, as the feed circuits for two orthogonal polarizations are placed on each side of the ground plane, respectively. By using a single patch, the prototype antenna designed at 2 GHz yields a bandwidth of more than 17% at both ports, and isolation below - 32 dB. Good broadside-radiation patterns are observed, and the cross-polar levels are below - 18 dB at both the E-and H-planes. This antenna will be useful for active phased-array applications as well as polarization-diversity applications where integration with other circuits at each port is needed.