Fast solvers for electromagnetic simulation of mixed-scale structures

In this paper, we propose a fast solver based on recently developed accelerated Cartesian expansion (ACE) algorithm. ACE is a tree code based algorithm like FMM but based on Cartesian harmonics instead of spherical harmonics. It can be shown that expansion in Cartesian harmonics is stable for low-frequencies unlike conventional FMM. Here, a method to combine ACE and FMM algorithm for efficient analysis of mixed-scale geometries is presented. Results demonstrating the viability of the fast kernel is presented here and their integration with MoM solvers will be presented at the conference.