Suppressing inside-substrate near-field magnetic coupling using SI-SRRs for the patch antenna arrays

Abstract

In this letter, we propose the decoupling technique of patch antenna arrays by suppressing near-field magnetic coupling (NFMC) using magnetic metamaterials unite cells. To this end, a highly-integrated linked magnetic metamaterial unite cells, 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 experiment results demonstrated that the isolation can be enhanced by more than 20.8dB even when the gap between the two patch antennas is only about 0.083λ. Due to high integration, this technique provides an effective alternative to high-isolation antenna arrays.