The use of the FFT for the efficient solution of the problem of electromagnetic scattering by a body of revolution

The enhancement of the computational efficiency of the body of revolution scattering problem is discussed with a view of making it practical for solving large body problems. The problem of the electromagnetic scattering by a perfectly conducting body is considered, although the methods provided can be extended to multilayered dielectric bodies as well. Typically, the generation of the elements of the moment method matrix consumes a major portion of the computational time. It is shown how this time can be significantly reduced by manipulating the expression for the matrix elements in a manner that allows one to compute them efficiently by using the fast Fourier transform (FFT). A technique for extracting the singularity of the Green´s function that appears within the integrands of the matrix diagonal is also presented, further enhancing the usefulness of the FFT. It is shown that, with the use of the method discussed here, the computational time can be improved by at least an order of magnitude for large bodies in comparison to that for previous algorithms