Numerical Computation of Dispersion Curves for Both Symmetric and Asymmetric Modes in Metal Coaxial Slow Wave Structures

In the overmoded coaxial slow wave structures (SWSs), the asymmetric mode is easier to be excited by the electron beam. For conveniently studying the high frequency characteristics of coaxial asymmetric modes, we derive and solve the universal dispersion equation for both symmetric and asymmetric modes in coaxial SWSs. In principle, this numerical formula can be applied to arbitrary even-function SWSs, arbitrary corrugated depth and arbitrary transverse dimension. By this dispersion equation, the dispersion curves of asymmetric modes can be calculated more quickly and conveniently than the simulation software based on finite-element method.