Design of a tri‐band multiple input multiple output antenna with high isolation for 5G applications

摘要

A novel tri‐band multiple input multiple output (MIMO) antenna with high‐isolation is proposed in this article. The proposed tri‐band MIMO antenna consists of two tri‐band monopole antennas placed symmetrically. Due to the ground surface wave, a defected ground structure (DGS) is etched to extend the ground surface current and reduce the port‐to‐port coupling. Then two ground branches are loaded on the ground plane as a reflector that inhibit and reflect the coupling between the two parasitic elements. In order to suppress the space surface waves, a novel non‐connected neutralization structure is loaded on the microstrip line of two monopole antenna elements. As a result, the quite good isolation and impedance matching are obtained by generating different resonance at different frequency of the structure. Finally, the proposed tri‐band MIMO antenna with the decoupling structure achieves 5G tri‐band of 2.5–2.7, 3.26–3.83, and 4.73–4.97 GHz (S11&S22 < −10 dB, S12 & S21 < −25 dB). The results show that the proposed tri‐band MIMO antenna can cover the whole 5G bands (sub‐6 GHz) and has good isolation characteristic, which can well meet the 5G applications.