The unimoment method applied to elliptical boundaries

A hybrid finite-element method (FEM) is presented for electromagnetic scattering by inhomogeneous dielectric cylinders of arbitrary cross section. The method employs an artificial elliptical boundary to enclose the scatterer and divide the solution region into interior and exterior regions. The field in the interior region is formulated using the FEM, and the field in the exterior region is represented by an eigenfunction expansion involving Mathieu functions. These fields are coupled at the elliptical boundary by enforcing field continuity conditions. A numerical example is given to demonstrate the advantages of the method.