Research on 8-unit MIMO antenna of 5G metal frame mobile terminal

To meet the antenna requirements of metal-framed mobile terminals in 5G era, an eight-unit MIMO array antenna composed of four "ring-slots" is proposed. In each "ring-slot" structure, the ring antenna and the slot antenna share a rectangular slot. Without adding an external decoupling structure, the current distribution around the rectangular gap is reverse and orthogonal, which realizes the high isolation of the structure. Through simulation and actual measurement, the center frequency of the MIMO antenna array is 3.5 GHz, which can work well in the LTE band 42(3.4-3.6GHz) of 5G communication. The isolation of the antenna unit is better than 16 dB, the radiation efficiency is between 65.8% ~ 73.7%, the envelope correlation coefficient is less than 0.02, and the radiation effect is good. The simulation and measurement results show that the proposed eight-unit MIMO array antenna has high compactness and isolation, and will be well applied to 5G metal frame mobile terminals to promote the progress and development of the 5G communication system.