Hybrid-mode analysis of circular waveguide with chiral dielectric lining for dispersion characteristics for potential application in broadbanding a gyro-traveling-wave tube

A circular waveguide with chiral dielectric lining was analyzed for hybrid mode dispersion relation. In chiral dielectric lining region, the different radial propagation constants, and in the central free-space region only one radial propagation constant for the left- and right- circularly polarized waves were considered. A method was presented to obtain the hybrid-mode dispersion relation of the proposed structure using the field matching technique. A numerical computer code was developed to solve the hybrid-mode dispersion relation and the solutions were plotted to explore the dispersion characteristics and shaping with the change of material and geometry parameters of the structure. Further, the azimuthal electric field intensity was plotted against radial coordinate to explore the position of field maxima for placing the gyrating electron beam for the potential application of the structure in a gyro-traveling-wave tube. Thus, out of the two modes studied, EH01 and HE01, the later found suitable for the operation of a gyro-traveling-wave tube.