Decoupling technique of patch antenna arrays with shared substrate by suppressing near-field magnetic coupling using magnetic metamaterials

In this paper, we propose the decoupling technique of patch antenna array by suppressing near-field magnetic coupling (NFMC) using magnetic metamaterials. To this end, a highly-integrated magnetic metamaterials, the substrate-integrated split-ring resonator (SI-SRR), is firstly proposed to achieve negative permeability at the antenna operating frequency. By integrating SI-SRR in between two closely spaced antennas, magnetic fields are blocked in the shared substrate due to negative permeability of SI-SRR, reducing NFMC between the two antennas. To verify the technique, a prototype was fabricated and measured. The measured results demonstrated that the isolation can be enhanced by more than 17 dB even when the gap between the two patch antennas is only about 0.067λ. Due to high integration, this technique provides an effective alternative to high-isolation antenna array.