Coupled Fem-Mmp For Computational Electromagnetics

The multiple multipole program (MMP) is a boundary method for computing electromagnetic fields, which is well established in high-frequency electromagnetics and computational optics due to its flexibility in terms of accuracy control, field excitation, and fast convergence. As any other boundary method, MMP cannot efficiently solve nonlinear problems. The purpose of this paper is to show a novel numerical method for treating local nonlinear regions within a large linear MMP model. The main idea of this approach is to apply the well-known discretization scheme of the domain finite-element method (FEM) within the nonlinear region and to couple it over a special numerical interface with the linear MMP model surrounding it. The theoretical details of this FEM-MMP coupling and practical examples are presented in this paper.