Design and Performance Evaluation of MIMO Antenna for 5G Smartphones

MIMO antennas play an important role in implementing the next generation of communication technology - 5G. This paper proposes a 4×4 MIMO antenna operating in the 3.3 - 4.2 GHz frequency range (N77 band for 5G) for 5G smartphones. The design is based on a shared radiator concept where two ports share one radiating element and are isolated from each other using an external decoupling structure. A radiating structure, the two ports, and a diode between the stub are considered a single element. Isolation between two ports is achieved using Mode - cancellation method and diode between the stubs that are placed between the ports. First, the antenna was designed for a single element to validate the design, and the same design was extended to realize a
$4\times 4$
MIMO antenna. Furthermore, the proposed design has achieved an isolation of ≥ 17dB and a gain ≥ 8 dB across the N77 band.