Propagation in the circular waveguide, containing an azimuthally magnetized ferrite cylinder and a dielectric toroid

The propagation of normal TE_0n modes in the circular waveguide, comprising a coaxially positioned ferrite cylinder with azimuthal bias and a dielectric toroid, of equal relative permittivities, is studied in terms of complex Kummer confluent hypergeometric functions and real Bessel and Neumann ones. The existence of certain positive real numbers (named L_3± numbers), related to the positive purely imaginary roots of the characteristic equation of configuration, is ascertained. It is found out that its phase curves for both signs of ferrite magnetization are finite, with limits, determined by the cutoff frequencies and by special envelope lines, depending on the quantities L_3±.