• A deep-learning-assisted optimization method combining ANN and PSO enables simultaneous port and radiation pattern decoupling in a metasurface-loaded 1×2 patch array.
• Measured isolation improved from 7.6 dB to 24.3 dB with an envelope correlation coefficient below 0.0005 at 0.35λ0 spacing.
• The prototype achieves 8% fractional bandwidth (4.8–5.2 GHz) with a compact footprint of 0.88λ0 × 0.47λ0 × 0.21λ0.
• Consistent and symmetric H-plane radiation patterns in the broadside direction make the antenna well suited for closely spaced MIMO systems.