Three-dimensional Finite-element Analysis of Conductivity and Dielectric Attenuation in Arbitrary Slow-wave Structure of Traveling-wave Tubes

This paper presents a novel 3-D finite-element analysis method for arbitrary lossy Slow-Wave Structure (SWS) of the traveling-wave tube. In this analysis method, a new Frequency-Specified Eigenmode Analysis (FSEA) for SWSs is proposed and utilized. Unlike the traditional phase-advance-specified eigenmode analysis for SWSs which has to solve a nonlinear Generalized Eigenvalue Problem (GEP), the new FSEA approach only needs solving a linear GEP and is capable of obtaining the attenuation constant more accurately and directly without any post-processing when simulating the lossy SWSs.