Theoretical analysis of ridge-loaded ring-plane slow wave structure by variational methods

The dispersion equation and interaction impedance of the ridge-loaded ring-plane slow-wave structure are obtained, by application of the Ritz-Galerkin method. Numerical results are given in terms of k-ν_p curves and impedance diagrams. The influence of several geometrical dimensions on the dispersion characteristic and interaction impedance are discussed. This kind of slow-wave circuit can operate at a high power level over a relatively wide microwave-frequency range. To get higher power and broader bandwidth for this circuit the optimum opening angle and a smaller radius of the loaded ridge must be chosen. The paper provides the theoretical basis for designing this type of slow-wave circuit for high-power travelling-wave tubes