Analysis of circularly non-symmetric modes in helical line externally loaded by azimuthally magnetized hollow ferrite cylinder

This work solves the problem of wave propagation in helical line externally loaded by azimuthally magnetized hollow ferrite cylinder. Computed dispersion curves are given. Attention is drawn to non-symmetric modes-as yet absent in the literature-since among them are the lowest order ones. The helical line, located on the inner surface of the ferrite cylinder is simulated by a non-reciprocal conductive cylinder (“sheath helix”). The electromagnetic field components inside the ferrite medium are expressed by special functions of the first and second kinds given by power developments and asymptotic expansions. For sufficiently thick ferrite cylinders the fields are essentially confined within the structure. The method allows analysis and design of non reciprocal phase shifters