A 5G MIMO Antenna for Broadcast and Traffic Communication Topologies Based on Pseudo Inverse Synthesis

Abstract

This paper proposes a new design of a dual-polarized base station antenna for sub-6-GHz 5G communication covering the band from 3.3 to 3.8 GHz. The proposed antenna offers a good impedance matching across the desired frequency band with $\text {VSWR} \le 1.5$ , a stable radiation pattern with a half power beam width of 65° ± 5°, and a high isolation between the ports with a small size and a low profile. The antenna is converted to a planar MIMO antenna array with low envelop correlation coefficients between the array elements to perform in either a broadcast or traffic communication topology whenever required. In the broadcast communication topology, the proposed MIMO antenna array covers a sector of 65° in the horizontal plane with three different down-tilted beam directions at 0°, 10°, and 20° in the vertical plane as conventional base station antennas used for 2G, 3G, and 4G. In traffic topology, the proposed MIMO antenna array can direct multiple beams to concurrent multiple users in a point-to-multipoint communication based on a novel pseudoinverse synthesis (PIS). The novel PIS is proved to be better than the other approaches which use spatial or frequency diversity as it possesses the advantage of the spatial diversity (by using a single frequency for multi-user coverage) and the advantages of the frequency diversity (by offering good steering capability and high directivity for each user). It is capable of radiating dynamic multiple beams simultaneously with an excellent flexibility and steering capability in real-time processing and outperforming other multi-beam antenna array methods. Thus, this new design is an ideal candidate for the new 5G mobile base stations.