Wave propagation through a waveguide segment with corrugated walls: The critical role of the corrugation sharpness

A theory of wave propagation in waveguides incorporating a finite-length segment with periodically corrugated side boundaries is developed. By now a lot of research papers on wave propagation in guiding systems with periodically varying parameters have been published [1,2]. In those papers, different effective-medium models were used to describe the wave propagation. These models take the account of the properties related to waveguide periodical nature, but they do not allow for all the peculiarities of wave scattering by uneven boundaries. The waveguide wall corrugation was normally assumed to be smooth, so the terms in the wave equation that are governed by corrugation profile derivatives were omitted by all of the authors.