A Review on Different Techniques of Mutual Coupling Reduction Between Elements of Any MIMO Antenna. Part 2: Metamaterials and Many More

Abstract This two-part article presents a review of different techniques of mutual coupling (MC) reduction. MC reduction is a primary concern while designing a compact multiple-input-multiple-output (MIMO) antenna where the separation between the antennas is less than ?0/2, that is, half of the free-space wavelength. The negative permittivity and permeability of artificially created materials/structures (Metamaterials) significantly help reduce MC among narrow-band compact MIMO antenna design elements. In this part two of the review paper, we will discuss techniques: Metamaterials; Split-Ring-Resonator; Complementary-Split-Ring-Resonator; Frequency Selective Surface, Metasurface, Electromagnetic Band Gap structure, Decoupling and Matching network, Neutralization line, Cloaking Structures, Shorting vias and pins and few more.