A Compact Reflector Assisted Four Port Planar Dipole MIMO Antenna for High-Gain 5G NR n79 Applications

Abstract The ever-increasing demand for high-capacity fifth-generation (5G) wireless communication systems necessitates the development of compact multiple-input multiple-output (MIMO) antennas with high gain, high radiation efficiency, and superior diversity performance for the sub-6 GHz New Radio (NR) n79 band (4.4-5.0 GHz). In this paper, a compact four-port planar dipole MIMO antenna is proposed with the reflector-assisted configuration to enhance simultaneously the radiation performance as well as the low-profile structure. The suggested antenna is constructed on a low-cost FR-4 substrate. The overall dimension of the antenna is 25 × 60 × 1.6 mm 3 . A stepped planar dipole geometry is used to achieve broadband impedance matching over the entire n79 band, and an optimized reflector is applied to enhance the forward radiation and suppress the backward radiation. The simulated and measured results show a bandwidth of 4.4-5.0 GHz for impedance with good port isolation and excellent MIMO performance such as envelope correlation coefficient (ECC) less than 0.04, diversity gain close to 10 dB, low channel capacity loss and good total active reflection coefficient (TARC). Furthermore, the proposed antenna achieves a radiation efficiency of more than 75% and a peak realized gain of more than 7 dBi, which outperforms the recently reported n79 MIMO antennas. These features show that the proposed design is a promising candidate for compact sub-6 GHz 5G NR wireless communication terminals.