IMPEDANCE MATRIX COMPRESSION USING ADAPTIVELY CONSTRUCTED BASIS FUNCTIONS

Wavelet expansions have been employed recently in numerical solutions of commonly used frequency-domain integral equations, In this paper, w e propose a novel method for integrating wavelet-based transforms into existing numerical solvers, The newly proposed method differs from th e presently used ones in two ways, First, the transformation is affect ed by means of a digital filtering approach, This approach renders the transform algorithm adaptive and facilitates the derivation of a basi s which best suits the problem at hand, Second, the conventional thres holding procedure applied to the impedance matrix is substituted for b y a compression process in which only the significant terms in the exp ansion of the (yet unknown) current are retained and subsequently deri ved, Numerical results for a few TM scattering problems are included t o demonstrate the advantages of the proposed method over the presently used ones.