Showing papers by "Yanyu Wei published in 2004"
TL;DR: In this paper, a linear theory was employed to analyze the start oscillation condition of the backward-wave oscillation in a helix traveling-wave tube (TWT) and showed that the attenuation length of the TWT decreases when the start position of the attenuator is close to the input section of the slow wave structure (SWS).
Abstract: In a practical helix traveling-wave tube (TWT), there is always attenuator/sever for suppressing the oscillations, including backward-wave oscillation (BWO). The factors of the influencing BWO include start position of the attenuator, its length, and attenuation quantity. In the event that the attenuator/sever and nonuniformities in the phase velocity and beam potential were considered, a linear theory is employed to analyze BWO start oscillation condition. Numerical results show that the start oscillation length of the TWT decreases when the start position of the attenuator is close to the input section of the slow wave structure (SWS), that Start oscillation current of the output section of the SWS increases as the attenuation length decreasing, or the attenuation quantity increasing or the nonuniformities becoming strong, and that, however, when the phase velocity or beam potential exceeds a particular value, no oscillation condition could be found.
22 citations
TL;DR: In this paper, a novel tape helix slow wave structure (SWS), which is supported by helically arrayed radial dielectric-support posts, is developed to enhance the power capability of the helix travelling wave tube.
Abstract: In order to enhance the power capability of the helix travelling wave tube, a novel tape helix slow wave structure (SWS), which is supported by helically arrayed radial dielectric-support posts, is developed. Each dielectric post can be easily brazed with the tape helix and the metal envelope by means of a special soldering. This kind of supporting mode can protect the dielectric supporting posts from being broken by the thermal stress in the case of high temperature. A hybrid model is set up in consideration of the influences of both the radial thickness of the tape helix and these discrete dielectric-support posts. The dispersion equation and interaction impedance of the helical SWS are obtained. The calculated results using this hybrid model presented in the paper show good agreements with the HFSS simulation results. All the results presented here can provide a good basis for designing the novel tape helix SWS.
9 citations