Large-signal 2.5-D steady-state beam-wave interaction simulation of folded-waveguide traveling-wave tubes

Journal
IEEE transactions on electron devices  
Volume
63
Issue
12
Start Page
4961
End Page
4967
Article Number
7733089
Citation
IEEE Transactions on Electron Devices 12 (63): 7733089 (2016-12)
Publisher DOI
10.1109/TED.2016.2616948
Scopus ID
2-s2.0-84995529472
A large-signal beam-wave interaction code for folded-waveguide traveling-wave tubes is presented. Formulation in frequency domain yields fast results of the steady state. The slow-wave structure is described by an equivalent circuit, while the electrons of the beam are modeled by means of a particle-in-cell approach. The latter exploits the periodicity of the electromagnetic fields in the beam tunnel region, thus allowing to work with a relatively low number of injected particles compared to conventional implementations. Physically consistent solutions are then obtained iteratively by incorporating the well-established Broyden's method. Further improvement in terms of computation time is achieved by initializing the iterative algorithm with results from previous simulations. The approach is verified by a comparison with published interaction simulation results. Single-frequency responses are obtained within a few minutes, which compares favorably with other specialized simulation packages and enables device optimization with acceptable effort.
Subjects
Folded waveguide (FW)
large-signal simulation
modeling
traveling-wave tube (TWT)