Rectangular Waveguide with Two Double Ridges

An eigenvalue equation of a general structure having two arbitrary double ridges in a rectangular waveguide is derived. The cutoff wavelengths of two special cases with two symmetrically placed identical double ridges is computed numerically and their bandwidths are compared. The numerical solution of the eigenvector is also discussed and utilized in determining the gap impedance. As an example of the applications of such ridged waveguides, two varactor-tuned Gunn oscillators are briefly reported.