Contribution to the Theory of the Two-Layered Ferrite-Dielectric Circular Waveguide

The effect of the material and geometry parameters on some traits of the circular waveguide, which contains a co-axially positioned dielectric cylinder and a ferrite toroid of azimuthal magnetization, and supports normal $T E_{01}$ mode, is examined. The method uses definite roots of its characteristic equation, deduced earlier in terms of complex Kummer and Tricomi confluent hypergeometric and real ordinary Bessel functions, and certain new real positive numbers ($\bar{L}_{4 \pm}$ and $\bar{L}_{4 \pm}$ numbers), advanced recently by the authors. With their help the lower and upper cut-off frequencies of configuration are calculated. Knowing them permits to find the width of the area in which it operates as a phase shifter. Assuming the anisotropy of the ferrite medium weak, a numerical study of the dependence of the quantities said is done on: i) the size of the section, occupied by dielectric, stipulating that the relative permittivities of the two layers are equal; i i) the dielectric to ferrite relative permittivities ratio, provided the first is larger than the second one and the axial isotropic cylinder is thin. A profound discussion of the outcomes is presented.