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

Abstract

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.

High Isolation Four-Port Wrench Shaped Compact Uwb Mimo Antenna for 3.1-10.6 GHZ Band

“…To reduce this mutual coupling, various mutual coupling (MC) reduction or decoupling, or isolation enhancement techniques were introduced in the literature. They are neutralization line (NL) [2], decoupling network (DN) [3][4][5][6], metasurface, metamaterial (MTM) [7], electronic band gap (EBG) [8,9], frequency selective surface (FSS), photonic band gap (PBG), optically transparent structures [10], split ring resonator (SRR), complementary split ring resonator (CSRR) [11,12], dielectric resonator antenna (DRA), ground plane modification (GPM), defected ground structure (DGS) [13,14], slots [15][16][17][18], band notching techniques implementation, parasitic elements, metal strips, shorting pins, insertion of stubs [19][20][21], frequency reconfigurable [22,23], implementing PIN diodes, microstrip open loop resonator (MOLR), quasi self complementary antenna (QSCA) [24], inter element spacing [25][26][27][28][29], insertion of slits, fractal structures, modified substrates, locating antennas on different substrate layers, etc. These techniques improve impedance matching, enhance gain, efficiency, and increase the complexity of antenna design.…”