Efficient recursive–iterative solution for EM scattering problems

An efficient recursive-iterative solution is proposed for electromagnetic (EM) scattering problems. The scheme involves dividing the impedance matrix of the method of moments into strong and weak interaction parts. The induced scattered current can be expanded in terms of the Taylor series. Then it can be solved recursively by the equations of the strong interaction part with multi-right-vectors that are related to the weak interaction part. The multilevel fast multipole method is used to accelerate the matrix-vector product operations of both strong and weak interaction parts. Moreover, the sparse approximate inverse preconditioner is applied to speed up the iterative convergence for equations of the strong interaction part. Numerical results confirm the accuracy and efficiency of the proposed method.