Nonstationary Nonlinear Discrete Model of a Coupled-Cavity Traveling-Wave-Tube Amplifier

Ryskin, Nikita M.; Титов, В. Н.; Yakovlev, A. V.

doi:10.1109/ted.2009.2016690

Cited by 30 publications

(41 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The DBE condition has been realized in microstrip transmission lines reported in 25 , and it has been demonstrated recently in fully-metallic circular loaded waveguides 26 . Some theoretical studies have discussed TWT operation very close to the edge of the EM band gap at a regular band edge (RBE), i.e., close to the cut-off frequency [15][16][17][27][28][29][30] , which is a different condition than the DBE explored here.…”

Section: Introductionmentioning

confidence: 91%

“…More elaborate descriptions account for non-linear effects in TWTs [15][16][17] , and a number of numerical methods have been developed incorporating full wave, particle-in-cell (PIC) techniques to accurately model waveguide-beam interaction 18,19 . Typically, periodic SWSs support several Bloch modes (propagating and evanescent), where each mode is represented by an infinite number of spatial Floquet harmonics 20 .…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Giant amplification in degenerate band edge slow-wave structures interacting with an electron beam

et al. 2016

View full text Add to dashboard Cite

We propose a new amplification regime based on synchronous operation of four degenerate electromagnetic (EM) modes in a slow-wave structure and the electron beam, referred to as super synchronization. These four EM modes arise in a Fabry-Pérot cavity (FPC) when degenerate band edge (DBE) condition is satisfied. The modes interact constructively with the electron beam resulting in superior amplification. In particular, much larger gains are achieved for smaller beam currents compared to conventional structures based on synchronization with only a single EM mode. We demonstrate giant gain scaling with respect to the length of the slow-wave structure compared to conventional Pierce type single mode traveling wave tube amplifiers. We construct a coupled transmission line (CTL) model for a loaded waveguide slow-wave structure exhibiting a DBE, and investigate the phenomenon of giant gain via super synchronization using the Pierce model generalized to multimode interaction.

show abstract

Section: Introductionmentioning

confidence: 91%

Section: Introductionmentioning

confidence: 99%

Giant amplification in degenerate band edge slow-wave structures interacting with an electron beam

et al. 2016

View full text Add to dashboard Cite

show abstract

“…Our algorithm dimoha is based on the Kuznetsov discrete model [12,13,[17][18][19][20][21][22][23] which uses an exact field decomposition for periodic structures for large-signal regimes. The SWS is directed along the z-axis with pitch d and cell index n ∈ Z.…”

Section: B the Discrete Modelmentioning

confidence: 99%

DIMOHA: A Time-Domain Algorithm for Traveling-Wave Tube Simulations

Minenna

Elskens

André

et al. 2019

IEEE Trans. Electron Devices

View full text Add to dashboard Cite

To simulate traveling-wave tubes (TWTs) in time domain and more generally the wave-particle interaction in vacuum devices, we developed the DIscrete MOdel with HAmiltonian approach (dimoha) as an alternative to current particle-in-cell (PIC) and frequency approaches. Indeed, it is based on a longitudinal N -body Hamiltonian approach satisfying Maxwell's equations. Advantages of dimoha comprise: (i) it allows arbitrary waveform (not just field envelope), including continuous waveform (CW), multiple carriers or digital modulations (shift keying); (ii) the algorithm is much faster than PIC codes thanks to a field discretization allowing a drastic degree-of-freedom reduction, along with a robust symplectic integrator; (iii) it supports any periodic slow-wave structure design such as helix or folded waveguides; (iv) it reproduces harmonic generation, reflection, oscillation and distortion phenomena; (v) it handles nonlinear dynamics, including intermodulations, trapping and chaos. dimoha accuracy is assessed by comparing it against measurements from a commercial Ku-band tapered helix TWT and against simulations from a sub-THz folded waveguide TWT with a staggered double-grating slow-wave structure. The algorithm is also tested for multiple-carriers simulations with success. PACS numbers: 45.20.Jj (Lagrangian and hamiltonian mechanics), 52.40.Mj (Particle beam interaction in plasmas), 84.40.Fe (Microwave tubes)

show abstract

“…The more recent discrete model (a.k.a. Kuznetsov discrete model) [14][15][16] is a promising tool to analyse such regimes beyond the capability of Pierce's model.…”

Section: Introductionmentioning

confidence: 99%

Recent discrete model for small-signal analysis of traveling-wave tubes

et al. 2019

View full text Add to dashboard Cite

equipe turbulence plasma, case 322 campus Saint Jérôme, av. esc. Normandie-Niemen, To perform accurate numerical simulations of the wave-particle interaction as it occurs in particular in traveling wave tubes, a new approach using field decomposition with large reduction of degrees of freedom has been proposed : the discrete model. To assess its validity, we compare it with the well-established Pierce equivalent circuit model in small signal regime.Before the comparison, the beam-wave interaction in both models is reformulated using a new pedagogical approach, dealing with associated beam, circuit-beam, and circuit impedances.We show analytically and with a numerical example that the newly developed reduced model is very close to the Pierce model. Interestingly, small deviations do exist at the edges of the amplification band, for which the reduced model offers a physical interpretation. PACS numbers: 84.40.Fe (Microwave tubes), 52.40.Mj (Particle beam interaction in plasmas)

show abstract

Nonstationary Nonlinear Discrete Model of a Coupled-Cavity Traveling-Wave-Tube Amplifier

Cited by 30 publications

References 16 publications

Giant amplification in degenerate band edge slow-wave structures interacting with an electron beam

Giant amplification in degenerate band edge slow-wave structures interacting with an electron beam

DIMOHA: A Time-Domain Algorithm for Traveling-Wave Tube Simulations

Recent discrete model for small-signal analysis of traveling-wave tubes

Contact Info

Product

Resources

About