Propagation in an azimuthally magnetized circular ferrite-dielectric waveguide

The propagation problem for normal TE_0n modes in a circular waveguide, containing coaxially positioned dielectric cylinder and azimuthally magnetized ferrite toroid, is solved by real cylindrical and complex confluent hypergeometric functions. The existence of certain positive real numbers (called L numbers), connected with the positive purely imaginary zeros of the structure´s characteristic equation, is established. As a result, the phase characteristics for both signs of ferrite magnetization turn out to be finite, restricted between the cutoff frequencies and special envelope curves, determined by the L numbers.