A Polarization Convert Reflective Surface-Based Wideband Antenna Array Decoupling Structure

This letter presents a wideband dual-polarized antenna array decoupling structure based on a polarization convert reflective surface (PCRS). The PCRS unit consists of a rectangular metal patch and a pair of symmetrical bow-shaped metal patches, which are printed on the top and bottom sides of a dielectric substrate, respectively. When a linearly polarized (LP) incident wave, for example, +45° LP wave, transmits through this PCRS, two orthogonal partially reflective (±45° LP) waves are generated concomitantly. These partially reflective dual-polarized waves neutralize the coupling wave between the antenna elements, which can significantly suppress the mutual decoupling between the copolarized and cross-polarized antennas. In order to obtain a wide decoupling band, a two-layer PCRS structure is used to generate more reflective waves and increase their path lengths. For verification, 1 × 4 dual-polarized array antennas with the PCRS are implemented. The results show that the isolations between the copolarized and cross-polarized adjacent antennas are increased from around 13 dB to better than 20 dB within 3.5–5.0 GHz (35.3%). In addition, simulation results reveal that the beam performance of the 1 × 4 array model is almost the same with and without using the PCRS. This indicates that the proposed PCRS has little effect on the antenna radiation performance.