Bi-Directional EBG for 4 × 4 Longitudinal and Lateral Mutual Coupling Reduction in MIMO Antennas for 5.8 GHz Applications

This paper presents the process of reducing the mutual coupling in both longitudinal and lateral directions of 2 × 2 (MIMO) antenna systems for 5.8 GHz applications. For size reduction, a bilateral EM band gap structure is added to the ground which helps in reducing the edge-to-edge distance between neighboring antennas rather than placing it between antenna elements. The results from Electromagnetic simulation and experimental measurements are discussed. A comparison between the use of the bilateral EBG between antenna elements to the non-using of any of the cases. For longitudinal isolation, the spacing between two opposite elements is 0.07 λ
0
and 11 dB isolation was achieved. For lateral isolation, the spacing between two elements is 0.5 λ
0
and 8 dB isolation was achieved. A measured isolation improvement is 10 dB for longitudinal isolation and 15 dB for lateral isolation.