Analysis of left-handed rectangular waveguides with dielectric-filled corrugations using the asymptotic corrugation boundary conditions

The asymptotic corrugation boundary conditions are employed to analyse left-handed rectangular waveguides with dielectric-filled transverse corrugations. The dispersion relations as well as the field expressions in the waveguide and the corrugation are derived. An equivalent multiport network model for the case of the two-walled corrugated waveguide is presented, and can easily be reduced to the one-walled case. Compared to the rather sophisticated full-wave solution, the asymptotic solution proves to provide accurate results within a wide frequency band. The limitations of the asymptotic boundary conditions are investigated to determine the range of validity of the presented solution.