Circular gyromagnetic waveguides with electric and magnetic walls

Circular waveguides with an electric wall and filled by a longitudinally magnetised gyromagnetic material are of interest in the area of ferrite phase shifters; the magnetic wall situation is employed in the design of ferrite resonators used in the construction of junction circulators. The latter waveguide, unlike the electric wall problem, for which only the phase constants are split, exhibits both split phase constants and cut-off numbers. Another notable feature of this class of waveguides is that a single continuous cut-off curve need not necessarily describe the same mode throughout its entire length. Such a discontinuity is displayed by the dominant mode of the magnetic wall waveguide but not by that of the electric wall problem. The purpose of this presentation is to give a tutorial introduction to this topic