Analysis of modal fields for rectangular corrugated waveguides

An efficient theoretical modelling of a rectangular waveguide with corner filled corrugations on four walls is described. This model allows accurate estimation of the modal dispersion behaviour of the structure without making any over simplified assumptions or encountering any inconsistencies in the boundary conditions. Although relying on numerical methods to obtain the dispersion behavior of the modes, the developed method provides a computationally efficient technique. Numerical results show a modal dispersion that significantly differs from that predicted by surface impedance models, and explains the bandwidth limitation of rectangular corrugated waveguides