Compact MIMO Antenna Design with SRR-Enhanced Isolation for Wireless Communication

Abstract

This paper introduces a compact antenna design with a partial ground plane, suitable for wireless communication systems. Implemented on a low-cost FR4-epoxy substrate, the antenna features a simple structure comprising a rectangular radiating patch. Simulations demonstrate excellent performance at 5.9 GHz, including a reflection coefficient (S<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">11</inf>) below −57 dB, a peak gain of 5 dBi, and an efficiency exceeding 90%.To enhance performance further, a MIMO configuration was explored, initially resulting in significant mutual coupling due to the close antenna proximity. To mitigate this, a linear Split-Ring Resonator (SRR) cells was strategically integrated into the antenna design. These SRR cells effectively reduced mutual coupling while preserving the antenna’s radiation characteristics. A substantial reduction in mutual coupling was observed across the entire operating bandwidth. Specifically, the transmission coefficients improved to −47.3 dB at 5.9 GHz and −36.2 dB at 4.7 GHz. This level of isolation minimizes interference between the antennas, enabling high-speed data transmission.In summary, this paper presents a novel and cost-effective design for compact, high-performance MIMO antennas for wireless communication. The proposed approach, combining a partial ground plane and SRR cells, provides a practical solution to the challenge of high mutual coupling in closely spaced MIMO antenna arrays.