Modeling of finite size vane-loaded helix slow-wave structures

Considering azimuthal space harmonics, the finite size vane model (FSV) is suggested for vane-loaded helical slow-wave structures (SWS) in this paper. Two vane-loaded helical slow-wave structures of TWT are calculated by the derived dispersion equations and the expression of interaction impedance. The calculating results are compared with the results of measurement and the calculating results of infinite number of vanes model (INV).