An FFT T‐matrix method for 3D microwave scattering solutions from random discrete scatterers

An efficient method to solve the scattering by a cluster of randomly located discrete scatterers is described. The scatterers can have an arbitrary shape, and only their T matrices need be known. An iterative method is suggested to solve this problem. To expedite the matrix‐vector multiply, we first aggregate the random scattering centers of the scatterers into centers that reside on a regular array. Then, the FFT method is used to perform the matrix‐vector multiply in O(N log N) operations. This method can solve a problem with a large number of unknowns, involving thousands of discrete scatterers, on a workstation.