Advanced Studies of the Differential Phase Shift in the Azimuthally Magnetized Circular Ferrite Waveguide

Two iterative methods are elaborated to determine the boundaries of the domain in that the circular waveguide, uniformly filled with azimuthally magnetized ferrite, provides differential phase shift for the normal TE01 mode. The peculiarities of the cut-off state of configuration and of its limiting one at higher frequencies in which the transmission for negative magnetization ceases, are the physical grounds for their formulation. The conception of first (second) approach is to compute the value of normalized in a suitable manner critical guide radius (radius, corresponding to a point of a specific envelope line in the phase portrait, depicting the limiting state) for a fixed numerical equivalent of the off-diagonal ferrite permeability tensor element in two ways: by a definite formula and by the root of structure's characteristic equation, derived through a certain complex Kummer function. The root is counted over and over again for a changing negative (positive) imaginary part of the first complex parameter of the latter, until the results for the radius coincide with a prescribed accuracy. The value of the imaginary part at that this happens is employed to reckon the phase constant of propagating mode, relevant to the state considered. The differential phase shift equals this constant in the first case, whereas in the second one, it is found from it by simple algebra. Varying the off-diagonal element, the borders of the domain in question are traced. The outcomes are presented graphically. The maximum value differential phase shift might attain at all is also calculated.