Departmental Papers (ESE)


The fast multipole method (FMM) was developed by Rokhlin to solve acoustic scattering problems very efficiently. We have modified and adapted it to the second-kind-integral-equation formulation of electromagnetic scattering problems in two dimensions. The present implementation treats the exterior Dirichlet (TM) problem for two-dimensional closed conducting objects of arbitrary geometry. The FMM reduces the operation count for solving the second-kind integral equation (SKIE) from O(n3) for Gaussian elimination to O(n4/3) per conjugated-gradient iteration, where n is the number of sample points on the boundary of the scatterer. We also present a simple technique for accelerating convergence of the iterative method: "complexifying" k, the wavenumber. This has the effect of bounding the condition number of the discrete system; consequently, the operation count of the entire FMM (all iterations) becomes O(n4/3). We present computational results for moderate values of ka, where a is the characteristic size of the scatterer.

Document Type

Journal Article

Date of this Version

June 1992


Copyright 1992 IEEE. Reprinted from IEEE Transactions on Antennas and Propagation, Volume 40, Issue 6, June 1992, pages 634-641.

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Date Posted: 05 July 2006

This document has been peer reviewed.