Design and Fabrication of a Compact 4-Element MIMO Antenna With High Isolation and Diversity Metrics for 5G Wireless Communications

Abstract This study addresses the design, manufacturing, and experimental validation of a small four-element multiple-input multiple-output (MIMO) antenna suited for sub-6 GHz 5G wireless systems. The antenna resonates at 5 GHz and uses connected patch elements with vertical slot perturbations for improved impedance matching and isolation. The constructed prototype has a peak gain of 10.29 dBi for the four-element arrangement, and measured isolation routinely exceeds 13 dB for adjacent antenna elements, with diagonal element isolation maintained above 28dB. Diversity performance demonstrates high reliability, with envelope correlation coefficients (ECC) below 0.01, diversity gain exceeding 9.99 dB, and mean effective gain (MEG) within acceptable bounds in the 4.7–5.2 GHz range. The device achieves minimal channel capacity loss (< 0.4 bits/s/Hz), steady group delay (< 1 ns), and around 85% radiation efficiency. An in-depth evaluation of scattering properties, radiation patterns, surface current distributions, and equivalent circuit modelling confirms the antenna’s capacity to minimize mutual coupling while maintaining substantial spatial variety. The excellent match between simulated and measured outcomes demonstrates the design’s correctness. The suggested MIMO antenna, with its compact form factor, good isolation, and great diversity performance, is a viable alternative for dependable high-throughput 5G sub-6 GHz wireless communication systems.