A Compact Hexagonal MIMO Antenna with Enhanced Band width And Isolation for Adaptive 5G 6G Applications

This paper presents a compact microstrip antenna array with enhanced isolation achieved using a hexagonal complementary split-ring resonator (CSRR) metamaterial structure. Mutual coupling between closely spaced antenna elements degrades radiation performance and limits MIMO system efficiency. To address this issue, a hexagonal CSRR is introduced between two identical rectangular patch antennas to suppress surface current propagation. The proposed structure creates a stopband effect at the operating frequency, effectively reducing electromagnetic interaction between the antenna elements. Simulation results demonstrate a significant improvement in isolation without increasing array size or degrading impedance matching. Surface current distribution analysis confirms that the CSRR efficiently blocks coupled currents between adjacent patches. Additionally, the antenna maintains stable radiation patterns and satisfactory gain characteristics. Due to its compact size, simple geometry, and effective mutual coupling reduction, the proposed antenna array is well suited for modern wireless communication and MIMO applications.

Keywords: Microstrip antenna array, mutual coupling reduction, complementary split-ring resonator (CSRR), metamaterial, MIMO antenna, isolation enhancement