High isolation circularly polarized MIMO antenna based on metasurfaces

In this article, a metasurface (MS) for decoupling circularly polarized (CP) antenna arrays is presented. The MS consists of periodic Jerusalem cross slot on one side of the substrate. MS can suppress space wave coupling by changing the coupling path. The distance between the centers of the antenna units is 30 mm (0.35λ₀). A 2 × 2 CP microstrip array coupled antenna is simulated and fabricated. The experimental results show that the mutual coupling between the E-plane and H-plane is reduced by 24 dB and 16 dB at the center frequency. It is worth mentioning that the antenna gain has been improved by 1.5 dBi.