Two-walled corrugated waveguide supporting backward waves: analysis using the asymptotic corrugation boundary conditions

In this paper, the dispersion relations were solved for the propagation constant for the one-walled and two-walled corrugated waveguides. The validity of the ACBCs solution were verified against the full-wave solution of and the limitations on the use of this asymptotic solution were investigated. The propagation constant was also obtained for even and odd modes and parametric studies were performed to exploit the use of the corrugation depths to tune the pass- and stop-bands and control the bandgap