Mixed Inner–Outer Iteration Technique-Based Surface Integral Equations for Fast Solving EM Scattering From Penetrable Objects

In this paper, a mixed inner-outer iteration technique based on surface integral equation is proposed for solving scattering problems from penetrable and homogeneous dielectric structures. The most important novelty of the proposed technique is combining the tangential Poggio-Miller-Chang-Harrington-Wu-Tsai as outer iteration and the electric-magnetic current combined-field integral equation as inner iteration, respectively. In this case, the new method offers the guarantee of high accuracy with faster convergence, especially for electrically dielectric structures in large scale. Furthermore, it presents an excellent compatibility with sparse approximate inverse preconditioning. Numerical results are given to demonstrate the accuracy, efficiency, and compatibility of the proposed method.