The role of analytical preprocessing in computational electromagnetics or why it may pay a lot to do a little analysis before jumping head-on into heavy computation

Summary form only given. It is shown that it is sometimes possible to alleviate problems in computational electromagnetics with a little analytical preprocessing, carried out before the relevant equations are translated into forms that are suitable for numerical computation. Three examples are considered. The first is that of the body of revolution problem, solved by the method of moments, for the oblique illumination case that requires a large number of azimuthal harmonics. The second example is the problem of scattering by a frequency-selective surface, which calls for a time-consuming evaluation of double summations that are characteristic of doubly periodic surfaces. The third example deals with the problem of mesh truncation when partial differential equation methods are used to solve the scattering problem. It is shown that for each of these cases it is possible to reduce significantly the computational time and/or memory over the brute-force approach.<>