Wideband Decoupled 8-Element MIMO Antenna for 5G Mobile Terminal Applications

A wideband decoupled dual-antenna pair is proposed and designed for 5G mobile terminal applications, with the help of characteristic mode theory. Parasitic strip and defective ground structure are used simultaneously to realize broadband and high isolation. Based on the proposed decoupled antenna pair, an eight-element multiple-input--multiple-output (MIMO) antenna is presented by placing four pairs at both side frames. By etching slits on the system ground, the mutual coupling between antenna pairs is effectively reduced. A prototype of the proposed antenna array is successfully fabricated and measured. Both simulated and experimental results indicate that the proposed eight-element MIMO antenna can completely cover n77/n78/n79 bands of the 5G New Radio and wireless local area network 5 GHz band. Furthermore, an isolation better than 15 dB is achieved between any two ports.