Characteristic Basis Function Method Combined With Krylov-Calderón Preconditioner for PMCHWT Formulation

We propose a novel characteristic basis function method (CBFM) for analyzing the scattering by dielectric objects based on the Poggio–Miller–Chang–Harrington–Wu–Tsai (PMCHWT) formulation. In the proposed method, the bases for electric and magnetic currents are orthogonalized with the help of the singular value decomposition (SVD), and are used as dual basis functions in a way similar to the RWG and Buffa-Christiansen (BC) basis functions. We show that the use of the Calderón preconditioner based on the Krylov subspace method together with the proposed method can prevent the poor convergence of the solution of the matrix equation in problems involving dielectrics. We considered different shapes of dielectric scatterers for validation purposes. The numerical results agreed well with those obtained by the conventional method of moments (MoMs) and the proposed method was faster than the conventional method. These results indicate that the proposed method is effective for scattering analysis of the dielectrics.