Fast algorithm for electromagnetic solution of modified-geometry problems

A fast algorithm is presented for the full-wave electromagnetic scattering solution of a class of modified-geometry problems. The algorithm assumes that the solution for a scattering structure, which, in general, may be composed of multiple scatterers, is known and stored. With the addition of a new scatterer to the problem, this algorithm avoids the solution of the modified problem from the beginning, and, instead, makes use of the stored solution of the original structure. This algorithm reduces not only the computation time but also the computational complexity of the solution from O(n/sup 3/) to O(n/sup 2/), if there are n unknowns in the problem.<>