Accelerated 3D Analysis of Metasurfaces for RIS Applications by Characteristic Basis Functions

A fast 3D numerical solver based on an electric field integral equation (EFIE) formulation is developed for analyzing metasurfaces (MTSs) in reconfigurable intelligent surface (RIS) applications. As part of the numerical model, a new methodology is introduced for the systematic generation of characteristic basis functions (CBFs). The CBFs provide a global approximation function set for the surface currents on PEC patches of the MTS cells with significantly fewer unknowns than regular localized expansion functions. Verification results are also provided.