Fast solution of scattering from 3D coating object by MLFMA with diagonal element approximation method

The multilevel fast multipole algorithm (MLFMA), combined with the diagonal element approximation method, is used to realize a fast solution of scattering from a 3D coated object. The impedance boundary condition (IBC) is used to approximate the real boundary condition. MLFMA based on conjugate gradient iteration is applied to expedite greatly the field computations from electric current sources and magnetic current sources. The diagonal element approximation (DEA) method is used to achieve an efficient solution of the sparse matrix equation. Numerical results show the present method is efficient for solving scattering from a 3D coated object with arbitrary shape.