An Eight-Element MIMO Array Based on Triple-Band Antenna Pair for 5G Smartphone Applications

A compact high-isolated eight-element MIMO array covers triple frequency bands of 5G communication is proposed. The multi-band operation is realized by etching slots at the grounded strip, and additional slot modes are well excited. Capacitor loading technology is adopted to expand the bandwidth and improve the isolation of the higher band. The mutual coupling reduction can be realized via the grounded shorting strip and the slits at the ground plane. The results indicate that the operation band covers 3.4-3.64 GHz, 4.8-5 GHz, and 5.15-5.95 GHz, and isolation between different ports is higher than 13.4 dB. With efficiencies of higher than 55%, the MIMO array is satisfying for 5G smartphone communication.