行波管放大器中场极限环和混沌行为的阈值分析

Threshold analysis for the limit cycle and chaotic oscillation of the radiation field in a traveling wave tube amplifier

以场方程和电子运动方程为基础 ,分析了行波管放大器中辐射场演化过程中出现极限环振荡和混沌态的电流阈值 .结果表明 :在某些参数范围内 ,辐射场会出现这些非线性不稳定态 .相互作用区域越长 ,失谐量对阈值的影响越明显 .当器件工作在非线性区域时 ,输出功率与电流、失谐量和相互作用区长度三个参数的关系变得紊乱无序 ,控制这三个参数在输出功率曲线的峰值点上 ,可在非线性区域获得较高的输出功率 .

In terms of the coupled equations of the radiation field and motion of the electron in a traveling wave tube amplifier, the threshold current at which the limit cycle or chaotic oscillation of the radiation field starts occurring is obtained. The result of numerical calculation shows that the nonlinear unsteady states may appear in a certain range of the parameters for the radiation field. The effect of the detuning on the threshold is relatively strong when the interaction region is longer. The relations of the output power with the three parameters (detuning, current and interaction length) become chaotic when the device operates in the highly nonlinear regime, and the higher output power can be obtained if the parameters are controlled suitably.