Dual-Beam MIMO Antenna Design Based on a Simple Decoupling Inductor

In this article, a dual-beam multiple-input and multiple-output (MIMO) antenna is presented, using a lumped inductor to reduce severe mutual coupling between two-closely spaced antennas. Using characteristic mode analysis (CMA), the decoupling mechanism can be revealed, which can be analyzed by coupling mode and decoupling mode. When two modes with anti-phase current distributions coexist around the operational frequency band, isolation enhancement can be achieved when both modes are simultaneously excited and superposed. The inductor-based decoupling strategy can be also applicable to patch antenna.