Closely arranged self-decoupled MIMO antenna group using orthogonal mode and pattern diversity for 5G mobile terminals

In this article, a novel self-decoupling method for closely arranged multi-unit antenna array design is proposed. The orthogonal mode and the pattern diversity are adopted to weaken the electromagnetic coupling between the multi-antenna elements. To verify the proposed self-decoupling concept, a closely arranged 4-port antenna group consisting of dual antenna pairs is designed. One of the antenna pairs is composed of overlapping loop antenna and monopole, and the other antenna pair shares a radiator, which are arranged on the upper and lower sides of the metal ground respectively. The proposed 4-port antenna group exhibits good isolation and complementary patterns without adding any extra decoupling structures. Based on the proposed self-decoupled 4-port antenna group, a 16 x 16 multiple-input multiple-output (MIMO) antenna array is constructed. The simulated and measured results show that the proposed 16 x 16 MIMO array has good antenna performance, such as isolation better than 15 dB, efficiency higher than 51% and channel capacity about 73 bps/Hz with 20 dB SNR. The proposed design concept is a great choice for highly integrated multi-antenna array and 5G mobile terminal.