Integral Equation based GSTC Solver using Characteristic Basis Function Method for Reflective Metasurfaces

This study introduces an accelerated integral-equation-based method for solving electromagnetic problems of composite structures including metasurfaces using the characteristic basis function method (CBFM). The metasurfaces are characterized by surface susceptibilities that satisfy the generalized sheet transition conditions (GSTCs). We consider structures composed of perfectly electric conductors, on which arbitrary metasurfaces are mounted. The Rao-Wilton-Glisson (RWG) basis functions are utilized to discretize the surface currents and to test the integral equations through Galerkin's method. Furthermore, the characteristic basis functions (CBFs) are used to reduce the number of basis functions. We conducted numerical simulations and compared the results with the results from commercial FEMbased full-wave simulations.