A hierarchical FFT algorithm (HIL-FFT) for accelerating marching-on-in-time methods

This article presents a hierarchical FFT-based algorithm that permits the fast analysis of transient electromagnetic scattering from uniformly meshed plate-like structures. For these structures the computational complexity of the algorithm scales as O(N/sub t/N/sub s/ log/sup 2/ N/sub s/). Similar to FFT-based algorithms for accelerating frequency-domain solvers, the HIL-FFT algorithm is more efficient (by a constant) than plane wave decomposition based algorithms when applied to the analysis of scattering from uniformly meshed structures.