Equivalent Circuit Analysis of a Ring–Bar Slow-Wave Structure for High-Power Traveling-Wave Tubes

A simple equivalent circuit analysis of the ring-bar slow-wave structure of a traveling-wave tube is developed, using the coupled transmission-line approach, for the dispersion and interaction-impedance characteristics of the structure. The effects of the ring and the bar widths of the structure are included in the analysis. The analysis is validated, with respect to 1) an X-band structure, against both measurement and simulation, as well as 2) a Q-band structure, against simulation.