The field feedback formulation for electromagnetic scattering computations

A new procedure is described for the solution of electromagnetic scattering problems in unbounded regions. Using this technique a spatial region enclosing the scatterer is initially decoupled from the exterior region and the fields therein are considered as the solution of an interior Dirichlet boundary value problem. The interior region solution is then recoupled to the unbounded exterior region by use of the equivalence principle. Such a process can be symbolically represented as a simple feedback system. The formulation is demonstrated for the case of plane wave scattering by finite metallic circular cylinders. A finite element solution of the interior problem is utilized in this example in conjunction with a field representation using a special case of coupled azimuthal potentials.