W波段损耗介质加载回旋返波振荡器中模式竞争的研究

摘要

本文采用自洽非线性理论模型系统研究W波段基波TE_（01）模回旋返波振荡器模式竞争的物理机理.通过采用特殊渐变的非谐振互作用结构和加载损耗介质抑制互作用系统中竞争模式,从而防止系统出现非稳态振荡现象.通过系统优化的互作用结构可以抑制竞争模式,能够稳定工作在TE_（01）模的轴向基模上.计算表明系统输出峰值功率105 kW,-3 dB调谐相对带宽为5.4%.这为发展应用于电子对抗、无损探测、等离子体诊断、材料处理等领域的宽带毫米回旋返波振荡器提供了理论基础,具有借鉴意义.%Mode competition induces non-stationary oscillations during the operation of a gyrotron backward-wave oscillator（gyro-BWO）, which severely reduces its tunable bandwidth and output power.Self-consistent nonlinear theory is used to study the modes-competition mechanism of a W-band fundamental TE01 mode gyro-BWO.Tapered non-resonant interaction circuit structure and loading lossy ceramic are employed to suppress the competing modes,as a way of preventing non-stationary oscillation in the circuit.Systematically optimized interaction circuit is capable of suppressing all the competing modes and can stably operate in the fundamental axial mode of the TE_（01） mode.Calculation indicates that a peak power of 105 kW and a—3 dB tunable bandwidth of 5.4%are attainable.This is meaningful and provides a theoretical foundation for developing broadband millimeter gyro-BWOs in the applications of countermeasure system,non-destructive detection,plasma diagnosis,material processing,and so on.