Dual-Polarized Antenna Arrays Based on Non-Uniform Partial Reflective Decoupling Layers for Vehicular Base Station Systems

In this paper, two non-uniform partially reflective decoupling layers (PRDLs) are applied to dual-polarized rectangular antenna arrays. By analyzing the coupled waves of the reference array and the reflected wave introduced by the PRDL, two-layer PRDLs are designed step-by-step. Compared to the array with only one-layer PRDL, the array with two-layer PRDLs can not only suppress various types of couplings but also improve the radiation performance. These PRDLs, which both have high dielectric constants in the two-dimensional plane, are composed of non-uniform artificial unit cells that are capable of reducing the cross-polarization discrimination (XPD) of the antennas while reducing the mutual coupling effectively. Simulated and measured results show that the isolation between antennas can be improved from 12 dB to more than 21 dB in the 1.71-2.2 GHz band, while the reflection coefficient remains below -15 dB. Compared with the reference array with no decoupling measures, the radiation pattern of the proposed array remains stable and the realized gain is increased. The proposed method is quite suitable for decoupling large-scale rectangular 5G MIMO arrays.