Design of a dual-polarized microstrip patch antenna with excellent polarization purity

In this paper, the design of a broadband dual-polarized microstrip patch antenna with excellent polarization purity is investigated theoretically and experimentally. Based on cavity-model theoretical analysis, a test dual-polarized microstrip patch antenna fed by double slot-coupled feeds with a 180° phase shift and a coplanar microstrip feed is presented. The simulated and measured results show that this antenna achieves a high isolation (< −41 dB) across the entire operating frequency and low cross-polarization level (< −30 dB).