Accelerated excitation-independent characteristic basis function method with multiscale adaptive cross approximation for monostatic radar cross section of dielectric objects

An accelerated excitation-independent characteristic basis function method (CBFM) combined with the multiscale adaptive cross approximation (MSACA) is proposed to analyze electromagnetic scattering from dielectric objects with volume equivalence principle. In CBFM, the adaptive cross approximation (ACA) is hybridized to improve the filling of mutual-impedance matrices, except for the mutual-impedance matrices of adjacent blocks, which are calculated by the timeconsuming method of moments (MoM). In this study, a new hybrid CBFM with MSACA is proposed to improve the filling of the mutual-impedance matrix, which achieves excellent effect. Moreover, an accelerated approach is adopted to remove the redundant excitations in advance by the ACA-singular value decomposition, leading to great reduction on the CPU time of the generation of the characteristic basis functions. The validity of the proposed method is illustrated with the systematic analysis of canonical geometries, and numerical results are given to demonstrate its efficiency and accuracy.