A compact two-port MIMO antenna with enhanced isolation using SRR-loaded slot-loop

In this paper, a compact two-port MIMO antenna is designed, which uses a shared orthogonally fed slot-loop, loaded with split-ring resonators (SRRs). The SRRs reduce the operating frequency of the slot-loop, leading to miniaturized antenna footprint of 0.059λ² (λ being the operating wavelength). Also the SRRs significantly enhance the inter-element isolation (>20 dB) in the working band. The proposed two-element MIMO slot-loop antenna exhibits bi-directional broadside radiation pattern with realized gain > 2 dBi in the operating band. Also the evaluated MIMO performance metrics like envelope correlation coefficient (ECC), channel capacity loss (CCL) and total active reflection coefficient (TARC), indicate satisfactory diversity performance. The design concept is validated by experiments on a fabricated prototype of the proposed MIMO antenna.