Inverse Design of Multiple-Input Multiple-Output Perfectly-Matched Metamaterials

Inverse design has been applied to a variety of complex electromagnetic structures including multifunctional and multiple-input multiple-output (MIMO) devices, where analytical design methods are limiting. We have previously reported on the inverse design of single-input, single-output Perfectly-Matched Metamaterials (PMMs). PMMs are inhomogeneous, anisotropic 2D metamaterials composed of unit cells that remain impedance-matched to each other and the surroundings under all excitations. PMMs rely primarily on refractive effects and exhibit broadband operation. This work presents the inverse design of a compact MIMO device based on PMMs: a 2D beamformer with prescribed amplitude and phase profiles that exhibits zero scan loss.