Verification of generalized telegraphist's equations applied to dielectric waveguide problems: comment

In accordance with the paper by So and Lee [Appl. Opt. 31, 6446-6452 (1992)], the efficiency of the Schelkunoff's method as applied to dielectric waveguide problems needs to be clarified. Previous papers have demonstrated the accuracy of the generalized telegraphist's equations in electromagnetic modal analysis on shielded dielectric waveguides as well as their application to electromagnetic-scattering properties. The basic mode-selection process can be clearly improved to get sharp reductions in CPU times and to assure very good solutions of slow, fast, evanescent, and complex waves. As a consequence, to analyze passive devices on dielectric waveguides, the cascaded set of multiple discontinuities model can be used. The modal matching technique has been used to demonstrate this possibility in calculating the generalized scattering matrix. Furthermore, the resulting electromagnetic field in a shielded dielectric waveguide structure can be used to calculate the cross-section dimensions of the metallic walls to simulate the dielectric configuration as in the open air.