A High-Gian Dual-Polarized MIMO Patch Antenna Array With Intrinsic High Isolation at Both E-/H-Planes

In this paper, a 1×4 high-gain dual-polarized highly isolated array is proposed based on the presence of multiple edge-weak-field-regions on the TM
12
-mode circular patch. At first, it is demonstrated that the marginal field of the patch is the main cause of coupling. By loading two cascaded slots in the center of the patch, the original strong E-plane electrical coupling is effectively reduced. Then, thanks to multiple weak-field regions at the edge of the patch, a slot-loaded TM12-mode patch element is readily extended into a 1×4 eight-port high-isolation array for dual-polarized realization. At last, the simulation results demonstrate that the proposed dual-polarized array can realize high isolation of more than 21.5 dB and element gain of 11 dBi with no need for any additional decoupling network.