Evaluation of boundary element analysis of electromagnetic wave scattering problems by the use of the condition number

This paper deals with three-dimensional electromagnetic scattering problems. The usual integral equations corresponding to electromagnetic scattering problems in general have the inconvenience of resonant solutions. Mautz and Harrington have derived an integral equation without such inconvenience. However, there are two arbitrary parameters contained in this integral equation. Further, when the integral equation is solved by numerical analysis based on the boundary element method, both expansion functions and weighting functions must be introduced. Although little flexibility exists in the selection of the expansion functions, two selection branches exist for the weighting functions. Hence, when the three-dimensional electromagnetic scattering problem is specifically analyzed numerically, selection of the parameters and the weight functions becomes important. Their selection should be carried out according to a reasonable evaluation standard. In the present paper, the condition number is used as the evaluation standard. It is shown which selection is the best among these choices. (C) 2003 Wiley Periodicals, Inc.