Design of corrugated waveguide filters by the Gel’fand–Levitan–Marchenko inverse-scattering method

A rigorous design rule of corrugated waveguide filters is developed by employing the Gel’fand–Levitan–Marchenko inverse-scattering method for the two-component coupled-wave equations of the Zakharov–Shabat type. In the course of developing the design method, the coupled Gel’fand–Levitan–Marchenko integral equations for the Zakharov–Shabat system having no discrete spectrum are shown to be reducible to a set of linear simultaneous equations amenable to simple numerical calculations when the reflection coefficient is a rational function.