A Dual-Polarized Microstrip Patch Antenna Based on AMC Surface with High Port Isolation

A high port isolation dual-polarized microstrip patch antenna based on artificial magnetic conductor (AMC) with an operating frequency of $9.3-9.5 \mathrm{GHz}$ is proposed in this paper. The antenna unit adopts two stacked patches and H-shaped slots coupled feeding to broaden the bandwidth. The design complexity of the feed network and the isolation are reduced by applying two orthogonal feed lines and metallic vias around them. The AMC surface is loaded below the feed lines to reduce the antenna profile based on zero-reflection phase characteristic. Moreover, the AMC surface reduced the electric field coupling between the slots on the ground and greatly improves the port isolation. The size of the antenna unit is $16 \mathrm{~mm} * 20 \mathrm{~mm} * 7.3 \mathrm{~mm}$. The simulated results show that the proposed antenna has a port isolation better than 48 dB and a cross-polarization level of -26dB. The profile of antenna is $7.3 \mathrm{~mm}\left(0.23 \lambda_{0}, \lambda_{0}\right.$ is the wavelength at 9.4 GHz), which provides a lower profile and higher port isolation compared to similar antennas.