【摘要】 目前回旋放大器的稳定性分析主要采用单模理论,而该理论不能分析模式间的相互影响。多模稳态理论可以分析不同模式间的相互影响,现有的多模理论仅可以分析光滑波导或内壁加载石墨涂层的波导结构,该结构并不适合高平均功率工作。本文首次将回旋行波放大器的多模稳态理论应用于适合于高平均功率的损耗介质加载波导模型,并分析了回旋返波振荡的存在对工作模式的影响。以TE₀₁模基波工作的Ka波段回旋行波管为例,研究介质损耗正切和输入功率的变化对回旋返波振荡的抑制作用。相较于使用PIC仿真方法,利用多模理论,可以快速地分析工作模式得到稳定放大的过程。更多还原

【Abstract】 A multimode steady-state theory was developed to theoretically analyze the beam-wave interactionin Gyro-Traveling Wave Tube（ Gyro-TWT） based on the lossy dielectric-loaded metal cylindrical waveguide. As exemplified by K-band gyro-TWT operating in TE₀₁ mode at high average power,the impact of the key variables,including the dielectric loss tangent,input power,radius of guiding-center,and electron velocity spread,on backward wave oscillations was investigated in the newly-developed theory. Besides,the multimode steady-state theory evaluated the correlation between the back-wave oscillation and operating modes and the ideal dielectric loss tangent required by the steady amplification in zero-driving state,overcoming the limitations of the single-mode theory. The results show that the increments of the input power and/or dielectric loss tangent effectively suppress the output power of backward oscillation modes,and that the guiding-center radius significantly affects the gain.更多还原