S/C dual-band high-isolation MIMO antenna based on metamaterial absorber

To achieve high isolation for S/C dual-band MIMO (Multiple-Input Multiple-Output) antennas, this paper designs a microstrip-fed ‘crab claw’ dual-band MIMO antenna coupled with a metamaterial absorber decoupling structure. The antenna employs a rectangular patch as its core structure. By incorporating rectangular slots and a 45-degree cut above the patch, stable resonance is achieved at 3.6 GHz (S-band) and 5.1 GHz (C-band). Drawing upon the principle of metamaterial surfaces for suppressing coupled waves, a ‘sandwich’ structure metamaterial absorber is arranged as a 1×3 absorber wall and mounted at the antenna's centre to absorb coupled energy. Simulation results indicate the antenna operates across 3.57– 3.74 GHz and 4.94–5.30 GHz, achieving isolation of 27.4 dB and 24.7 dB respectively within these bands (full-band isolation ≥23.3 dB); The envelope correlation coefficient (ECC) is