PERIODIC WAVELET EXPANSIONS FOR ANALYSIS OF SCATTERING FROM METALLIC CYLINDERS.

The recent application of wavelet transforms in method-of-moments solutions for scattering problems is extended to cases involving metallic cylinders whose periphery contain a variety of length scale features ranging from smoothly varying large-scale features to rapidly varying small-scale ones. The basic idea is to first consider a periodic extension of the equivalent current in the arc-length variable with a period identical to the scatterer circumference, and then to expand this representation, using a set of periodic wavelets derived from a conventional basis of wavelets by a periodic extension. Using a Galerkin method and subsequently applying a threshold procedure, a substantial reduction in the number of elements of the moment-method matrix is attained without virtually affecting the solution accuracy. The proposed extension is illustrated by a numerical study of TM (transverse magnetic) scattering from a cylinder of elliptic cross section. [ABSTRACT FROM AUTHOR]