Investigation of Dispersion Characteristics in Coaxial Disk-Loaded Slow-Wave Structures With Both Symmetric and Asymmetric Modes

Coaxial disk-loaded waveguide has been widely used in magnetically insulated transmission line oscillators. Although the TM₀₀ mode is its main mode, the asymmetric mode might be excited by a slight asymmetry of the structure, asymmetric emission of the beam, or both. Therefore, research on the asymmetric mode in coaxial disk-loaded waveguide is necessary. The general dispersion equation of the coaxial disk-loaded slow-wave structures is obtained using the field match theory for the first time. Numerical calculation is carried out based on the dispersion function. The theoretical calculated results agreed well with the simulated results of the MAFIA code and experiment.