Direct solution of electromagnetic scattering from perfect electric conducting targets using multilevel characteristic basis function method with adaptive cross approximation algorithm

The adaptive cross approximation (ACA) enhanced multilevel characteristic basis function method (MLCBFM) is studied in this article. It is well known that the impedance submatrices containing the reaction terms of low-level basis functions such as Rao-Wilton-Glisson basis functions have low-rank property. However, the authors find that the high-level impedance matrices between nonoverlapping high-...