宽带大功率螺旋线行波管返波振荡研究

Backward-wave oscillation in high power broadband helical traveling wave tube

在一维场论注-波互作用理论的基础上,引入磁场对角向速度的影响,建立了二维非线性返波注-波互作用理论,模拟返波振荡.对不同空间电荷参量下起振长度的变化进行了小信号分析比较,结果与等效线路模型比较接近;对某8—18GHz行波管进行了实测比较,结果也比较一致.同时还研究了影响返波振荡起振长度的因素,提出了该管的抑制返波振荡方案.

A 2D nonlinear beam-wave interaction is built to simulate the backward-wave oscillation（BWO） in a Helical traveling wave tube,based on the 1D beam-wave interaction model by taking into account the angular speed which is affected by magnetic field. The normalized oscillation start-up length with different space charge parameter is compared with that obtained from a equivalent circuit model in small signal,showing that they are close to each other. Also,the simulated results are in accordance with the measurements in a 8—18 GHz Helical TWT. The factors affecting the BWO are studied, by which some methods to suppress the BWO are improved.