A nonlinear analysis of the terahertz serpentine waveguide traveling-wave amplifier

Journal Article · Wed Apr 15 04:00:00 EDT 2015 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.4917526· OSTI ID:22408352

Li, Ke; Cao, Miaomiao ^[1]; Liu, Wenxin; Wang, Yong ^[1]

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1. Key Laboratory of High Power Microwave Sources and Technologies, Institute of Electronics, Chinese Academy of Sciences, Beijing 100190 (China)

A nonlinear model for the numerical simulation of terahertz serpentine waveguide traveling-wave tube (SW-TWT) is described. In this model, the electromagnetic wave transmission in the SW is represented as an infinite set of space harmonics to interact with an electron beam. Analytical expressions for axial electric fields in axisymmetric interaction gaps of SW-TWTs are derived and compared with the results from CST simulation. The continuous beam is treated as discrete macro-particles with different initial phases. The beam-tunnel field equations, space-charge field equations, and motion equations are combined to solve the beam-wave interaction. The influence of backward wave and relativistic effect is also considered in the series of equations. The nonlinear model is used to design a 340 GHz SW-TWT. Several favorable comparisons of model predictions with results from a 3-D Particle-in-cell simulation code CHIPIC are presented, in which the output power versus beam voltage and interaction periods are illustrated. The relative error of the predicted output power is less than 15% in the 3 dB bandwidth and the relative error of the saturated length is less than 8%.The results show that the 1-D nonlinear analysis model is appropriate to solve the terahertz SW-TWT operation characteristics.

• OSTI ID: 22408352
• Journal Information: Physics of Plasmas, Journal Name: Physics of Plasmas Journal Issue: 4 Vol. 22; ISSN PHPAEN; ISSN 1070-664X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
AMPLIFIERS
COMPUTERIZED SIMULATION
ELECTRIC FIELDS
ELECTRIC POTENTIAL
ELECTROMAGNETIC RADIATION
ELECTRON BEAMS
FIELD EQUATIONS
GHZ RANGE
HARMONICS
INTERACTIONS
NONLINEAR PROBLEMS
RELATIVISTIC RANGE
SERPENTINE
SPACE CHARGE
THZ RANGE
TRAVELLING WAVE TUBES
WAVE PROPAGATION
WAVEGUIDES