Efficient 10-element MIMO antenna array design for wideband 5G smartphone applications.

A miniaturized ten-element MIMO antenna array for sub-6 GHz 5G mobile devices is introduced in this work. The structure covers a broad band from 3.2 GHz to 6.2 GHz, which provides isolation of more than 19 dB, extremely low ECC < 0.01, and high efficiency between 78% and 85%. The antennas are located on the edge of a 150 mm x 80 mm FR4 substrate, which can be approximated to 1.6 λ × 0.85λ at f0 = 3.5 GHz, and each antenna size is 0.11 λ × 0.03λ, which has been optimized to provide wide-band coverage by using proper current distribution on the slots. Under different operating positions, e.g., single-hand, two-hand conditions, and under various obstacles such as batteries, LCDs, the antennas maintain their high efficiency and peak channel capacity, i.e., 46-50.25 bps/Hz, which confirms the ability to meet the high data rate requirements of 5G. In addition, due to its small size and excellent performance, the new antenna array could also be used in different wearable devices, ultrathin laptops, and other IoT terminals requiring high-performance MIMO antennas in sub-6 GHz 5G and beyond.