Multilayer Metasurface Simulation in FDTD using Surface Susceptibility Model

Multilayer designs of metasurfaces are required for practical applications because they have more capability to manipulate electromagnetic wave than single-layer designs. This paper thus extend the Surface Susceptibility Model (SSM) integrated in FDTD from single layer to multilayers, consequently accelerating metasurfaces simulations with good accuracy. The SSM is integrated in FDTD by using Generalized Sheet Transition Conditions (GSTCs). To demonstrate the validity of the proposed algorithm, a numerical comparison is presented between simulation of two layer geometrical structures in conventional FDTD and two layer surface susceptibility model in FDTD-SSM.