大功率毫米波行波管AM/PM转换特性大信号解析理论的研究

Analytic exploration of AM/PM conversion characteristics of high power millimeter-wave traveling wave tubes using Eulerian hydrodynamic analysis

基于相位展开的欧拉大信号理论,采用逐次逼近法推导得到场和AM/PM转换(输出相位对输入功率的导数)的大信号解析解。以一支Q波段毫米波行波管为例,将大信号解析解与拉格朗日理论以及传统欧拉非线性理论进行对比。结果表明:大信号解析解的功率、增益和相移以及AM/PM转换与拉格朗日理论在线性区和中度互作用区十分吻合,饱和增益最大误差小于8. 5%。同时大信号解析解相较于传统的欧拉非线性模型具有更高的精度,且能表现出饱和现象。

Based on the phase expansion nonlinear Eulerian beam-wave interaction theory model of millimeter-wave traveling wave tubes,Eulerian large-signal analytic solutions of electric field and AM/PM conversion are obtained by the method of successive approximation.Then,the Eulerian large-signal analytic solutions are compared to a Lagrangian beam-wave interaction theory model and traditional Eulerian nonlinear models.All the simulations are conducted on a set of millimeter-wave traveling wave tube parameters which are based on a single pitch section of a Q-Band traveling wave tube.It is found that the gain,phase and AM/PM conversion of Eulerian large-signal analytic solution agree well with Lagrangian beam-wave interaction theory model before saturation occurs.The maximum error of gain is less than 8.5%near saturation.The Eulerian large-signal analytic solution gain more accuracy than traditional Eulerian models.The present Eulerian large-signal analytic solution can describe saturation effects which is caused by electron overtaking that cannot be found by traditional Eulerian analysis.Results validate the correctness and effectiveness of our Eulerian large-signal analytic solution and the analytic solution of AM/PM conversion.