A Dual-Band Dual-Polarized Antenna Array with Improved Isolation

In this work, a dual-band dual-polarized microstrip antenna array is presented with well cancelled self-interference resulting from the couplings within the array for co-time co-frequency full-duplex communications. The proposed single dual-band dual-polarized antenna uses multi-layer architecture, where feedings in shunt and in series are adopted for the two polarizations, respectively. A symmetrical array scheme collaborated with specified excitations is proposed for array applications to further improve the isolation level. A $\pmb{1 \times 4}$ array operated at 2.45 GHz and 3.5 GHz is designed for verification. Simulated results show that the isolations are higher than 60 dB for the two impedance bandwidths with $\pmb{\vert \text{S}_{1,1}\vert \leq-10\text{dB}}$.