Equivalent Multisector Analytical Method for High-Frequency Characteristics of Integrated Three-Helix TWT

An equivalent multisector analytical method is proposed for the high-frequency characteristics of the slow-wave structure (SWS) in an integrated three-helix traveling wave tube. The discrete unit in the SWS is divided into multiple regions, and every region is treated equivalently as a sector using the equal area method. The accuracy of the equivalent multisector structure is verified by comparing it with an equivalent circular structure and the original SWS in computer simulation technology (CST). The analytical solution for high-frequency characteristics of the equivalent multisector structure is obtained by using the tape-helix model and the infinite number of vanes model. The calculation result is obtained and compared with the CST simulation result to analyze the accuracy of the method. The maximum error for dispersion characteristics and coupling impedance is 5.3% and 6.1%, respectively, so the feasibility of the analytical method is verified.