An Approach to Thermal Analysis of Helically Corrugated Waveguide Elements of Vacuum Electron Devices

Metallic helically corrugated structures play an important role in microwave vacuum electron devices serving as wave converters, wave compressors, and interaction circuits. Thermal analysis of such structures operating in a high-power regime is important for their design and development. In this paper, an algorithm for an efficient analysis of temperature distribution in helically corrugated metallic structures caused by Ohmic losses in their walls is presented. The algorithm is based on the coordinates transformation with the subsequent expansion of the equations to the Fourier series with respect to the longitudinal coordinate. The advantages and limitations of the algorithm are discussed. Comparison with a 3-D finite-element simulation was performed, and a sufficiently good agreement was demonstrated.