Analysis of Isolation Techniques for Mutual Coupling Reduction in MIMO Antennas

—This paper presents a comprehensive review of isolation enhancement techniques for MIMO systems, emphasizing their role in minimizing mutual coupling for modern wireless communication applications. Seven main reduction couplings are found, such as neutralization lines (NL) structures, metamaterials that included electromagnetic band gap (EBG) and meta-surfaces, parasitic elements (PE), defected ground structures (DGS), decoupling networks (DN), and hybrid isolation techniques. Each technique has been discussed and analyzed based on design geometry, methods, and reduction coupling performance. Depending on the results of using these techniques, the study found there was a good enhancement of isolation, ECC and other antenna performance. In addition, this work draws attention to the effectiveness of combining methods for compact and high-performance antennas. Also, the composition of the previous studies was deeply analyzed in terms of size, isolation, bandwidth, distance and value of isolation enhancement. This work covered the published papers for 5G communication bands to be a base station for designing MIMO antennas with high isolation.