Cut-off Characteristics of the Normal on Modes in the Circular Waveguide Containing an Azimuthally Magnetized Ferrite Cylinder and a Dielectric Toroid

A method for computation of the positive purely imaginary roots of the characteristic equation of the circular waveguide with a ferrite cylinder of azimuthal magnetization and a dielectric toroid, propagating normal TEon modes, derived by complex Kummer confluent hypergeometric and real Bessel and Neumann functions, is developed. Employing it, a numerical analysis is performed of the dependence of those of them which correspond to a zero imaginary part of the complex first parameter of Kummer functions, on the modulus of off-diagonal ferrite permeability tensor element vertical bar alpha vertical bar and the anisotropic cylinder to transmission line radius ratio rho, assuming equal values of the relative permittivities of the two media. The discussion is confined to the first roots only - to the TE01 mode. Based on this study, the cut-off characteristics of the latter in the configuration (the distribution of the normalized towards frequency and ferrite relative permittivity critical guide radius for the same vs. rho with vertical bar alpha vertical bar as parameter and to vertical bar alpha vertical bar with rho as parameter) are (is) counted. The results obtained are illustrated numerically and graphically. They could be used in designing nonreciprocal microwave ferrite control components.