A Review of Isolation Techniques for 5G MIMO Antennas

This paper offers an analysis of mutual coupling reduction techniques used in MIMO antennas designed for sub-6 GHz, 28 GHz, and 28/38 GHz dual frequency bands which are allocated to 5G technology. The said techniques take into account size, gain, isolation, and all diversity-related parameters, such as envelope correlation coefficient (ECC), directive gain (DG), and channel capacity loss (CCL). A review of current technologies is presented in the paper too. The isolation techniques are studied in detail and comparisons between the various works are drawn. Finally, the best isolation technique suitable for specific bands, applications and different port numbers is determined.