Ridged Waveguides with Inhomogeneous Dielectric-Slab Loading

The dispersion equation of the ridged waveguide with inhomogeneous dielectric-slab Ioading is derived. Numerical results for the cutoff frequencies of the three lowest order TE_m0 modes are given which substantiate the feasibility of the modal expansion and field-matching technique employed. For a Teflon-slab loaded ridged waveguide, a 40-percent decrease of dominant-mode cutoff frequency, simultaneously providing 20-percent enhanced TE₂₀-mode separation compared to an empty ridged waveguide, is demonstrated.