A Simple Decoupling Method for 5G Millimeter-Wave MIMO Dielectric Resonator Antennas

A simple decoupling method of using metallic vias to improve the isolation of millimeter-wave (mm-wave) multipleinput- multiple-output (MIMO) dielectric resonator antenna (DRA) elements is investigated. The vias are vertically added into the DRA elements, at appropriate positions. By means of the interaction with the electromagnetic (EM) fields, the vias can potentially affect the filed distributions and further reduce the coupled fields effectively. The isolation between the MIMO DRA elements can therefore be enhanced substantially. As the vias are placed inside the DRA elements, no extra footprint is needed, making the entire antenna system very simple and compact. Two typical examples, including an H-plane and an E-plane coupled 1×2 MIMO DRA arrays, have been designed, fabricated and measured to demonstrate the feasibility and universality of this method. The results show that by using the vias appropriately, the isolation of the H-plane coupled MIMO DRA array can be enhanced from ~15.2 to 34.2 dB, while that of the E-plane array can be improved from ~13.1 to 43 dB at 26GHz.