A Highly Selective Spatial Filtering Design for 5G Massive MIMO Patch Antenna Array

This paper proposes and designs a spatial filtering structure for 5G base station Massive MIMO antenna array with excellent out-of-band suppression and low in-band insertion loss characteristics. This structure is a type of second-order highly selective bandpass frequency selective surface (FSS) which is periodically arranged on the front of a dual-polarized stacked patch antenna array. This structure is simulated and verified by CST and the result shows that it can perform effectively as a single-passband spatial filtering on 5G low-frequency communication band (3.4-3.6GHz) with a 3dB bandwidth from 3.38GHz to 3.61GHz. It also has low in-band insertion loss, and excellent upper and lower sideband suppression.