Effect of a backward wave on the stability of an ultrahigh gain gyrotron traveling-wave amplifier

Journal Article · Mon Dec 15 04:00:00 EST 2008 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.3041161· OSTI ID:21259739

Chaohai, Du ^[1]; Pukun, Liu; Qianzhong, Xue ^[1]; Minghong, Wang ^[2]

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1. Institute of Electronics, Chinese Academy of Sciences, P.O. Box 2652, 100190, Beijing (China)
2. School of Physics Science and Information Engineering, LiaoCheng University, 252059, Shandong (China)

A systematic stability analysis method using theoretical tools combining linear and self-consistent nonlinear theory is presented to analyze an ultrahigh gain gyrotron traveling-wave (gyro-TWT) amplifier operated in the fundamental TE{sub 11} mode in the Ka-band. It characterizes the role that the backward-wave component plays in the internal feedback physical processes of two major kinds of self-induced oscillations associated with TE{sub 11}{sup (1)} absolute instability and TE{sub 21}{sup (2)} gyrobackward-wave oscillation. For the first time, self-induced constriction in TE{sub 11}{sup (1)} absolute instability caused by a strong backward-wave component is revealed through simulation. Both the thickness and resistivity of the distributed wall loss loaded on the inside of the interaction waveguide have obvious effects on stabilizing both kinds of oscillations. Following the stability analysis, a multistage interaction circuit is proposed by nonlinear analysis which shortens the length of the entire structure and enables the ultrahigh gain gyro-TWT to operate with high stability and wide bandwidth.

• OSTI ID: 21259739
• Journal Information: Physics of Plasmas, Journal Name: Physics of Plasmas Journal Issue: 12 Vol. 15; ISSN PHPAEN; ISSN 1070-664X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
ABSOLUTE INSTABILITIES
MICROWAVE AMPLIFIERS
NONLINEAR PROBLEMS
OSCILLATIONS
STABILITY
TRAVELLING WAVES