Dual-Band Highly Isolated Eight-Element MIMO Antenna for 5G Mobile Phone.

Based on the characteristic mode analysis (CMA) theory, a compact dual-band dual antenna pair with high element isolation function for 5G mobile terminal is proposed and designed in this paper. The antenna pair is composed of a pair of symmetrical stacked Fshaped radiators printed on the outside of the side frame, perpendicular to the main board. Based on the proposed decoupled antenna pairs, four pairs of antenna pairs are placed at both ends of two long side plates, and an 8-element MIMO antenna is proposed. High isolation in the operating frequency bands are achieved by using grounding branches and defective ground structure (DGS). All radiation elements are etched on a low-cost FR4 substrate with a total size of 150 χ75χ 6.8 mm3. The prototype of the antenna array is fabricated and measured. The working range of the antenna pair can cover 3.4GHz-3.6GHz,4.8GHz-5GHz 5G frequency bands and 5GHz-6GHz WLAN / WiFi / WiMax frequency bands. Besides, the isolation between any adjacent array elements are also > 15dB and > 16dB respectively, the total efficiency are 52%--75% and 58%--88% respectively, and the measured envelope correlation coefficients (ECC) are <0.16. Furthermore, user's head effects are investigated and desirable results are obtained. The above results show that this proposed antenna array is a good candidate for MIMO applications in 5G smartphones. [ABSTRACT FROM AUTHOR]