A UNIQUELY SOLVABLE INTEGRAL-EQUATION FOR THE EXTERIOR ELECTROMAGNETIC SCATTERING PROBLEM

We are concerned with the exterior electromagnetic scattering problem in which the time dependence is harmonic and the scatterer is perfectly conducting. When this problem is formulated in terms of a surface integral equation there is normally the difficulty that the integral equation lacks a unique solution for certain values of wave number. In the following we shall first derive a surface integral equation of the first kind which involves a Green's tensor I°. The lack of uniqueness with this 'natural' choice of tensor is then demonstrated. Consequently a modification is made to I° which is shown to lead to a unique solution in the surface integral equation. © 1987 Oxford University Press.