New scattering theory for CAD of dielectric waveguide discontinuity

A new scattering theory for the computer-aided design (CAD) of dielectric waveguide discontinuities is presented. As a simple example, a new volume integral equation for the scattering by an arbitrary-shaped end in the dielectric waveguide is shown. The new theory indicates that zero of the scattering coefficient at the angle of waveguide direction is the fundamental relation for the mathematical formulation of the problem. By using this relation, one can treat the scattering problems of dielectric waveguide discontinuities as scattering problems of an isolated finite-sized object. The basic idea of the new theory is very general. Hence, this theory is applicable to the more complicated waveguide discontinuities such as waveguide bends and waveguide branches.<>