Boundary Element Analysis of Three-Dimensional Scattering Problems by Extended Integral Equation.

A new extended integral equation is introduced for three-dimensional electromagnetic scattering problems, and a method is proposed for analyzing this extended integral equation numerically by means of a new boundary element method in which vector shape functions are used. In the conventional boundary integral equation, there is no unique solution to the electromagnetic wave at the angular frequency coinciding with the one characteristic to the system. Several methods are proposed for alleviating this problem; however, each has its own problem. This paper proposes an extended integral equation in which the observation points are allocated on a closed surface in- side the scatterer adjacent to the scatterer surface. Not only does the extended integral equation proposed in this paper a frequencies, hut also it overcomes various deficiencies of the conventional integral equation method. in this paper, the extended integral equation for a three-dimensional perfectly conducting scatterer is derived first and its uniqueness of the solution is proven. Further, for practical examples, this extended integral equation is solved numerically by means of the new boundary element method using vector shape functions. The uniqueness and accuracy of the solution are studied numerically. [ABSTRACT FROM AUTHOR]