Dielectric resonator magnetoelectric dipole arrays with low cross polarization, backward radiation, and mutual coupling for MIMO base station applications

Dielectric resonator magnetoelectric dipole (DRMED) arrays with enhanced isolation, reduced cross-polarization, and backward radiation are proposed for base station (BS) applications. The proposed antenna comprises an elevated dielectric resonator antenna (DRA) on a small metal plate above a sizeable common ground plane. The DRA is designed in its TE_δ11 mode, acting like a magnetic dipole. The surface current excited by the differential probes flowing on the small ground plane is equivalent to an electric dipole. Since these two equivalent dipoles are orthogonal, they have the magnetoelectric dipole characteristics with reduced backward radiation. Meanwhile, the small ground planes can be treated as decoupling structures to provide a neutralization path to cancel the original coupling path. A linearly-polarized 4-element prototype array was verified experimentally in previous work. Here, a dual-polarized DRMED antenna is presented to construct a 2-element and 4×4 array for BS applications. To investigate its MIMO performance, sophisticated multi-cell scenario simulations are carried out. By using the proposed dual-polarized DRMED array, the cellular system capacity is improved by 118.6% compared to a conventional DRA array. This significant MIMO system improvement is mainly due to the reduced backward radiation and, therefore, reduced inter-cell interferences. Measurements align well with the simulations.