中文摘要：

研究了分布损耗材料导电特性的下降能够增强回旋行波管注-波互作用段对电磁波的衰减,提高了绝对不稳定性振荡的起振电流和竞争模式回旋返波振荡的起振长度;但同时减小了回旋行波管的线性增长率及其轴向功率和高频场增益。给出了石墨乳涂敷圆波导结构回旋行波管工作参数,采用电子束电流I0=10A、注-波互作用段长度L=10cm时的设计结果,在兼顾功率和增益的条件下,能够有效抑制不稳定性,保证其稳定工作。

英文摘要：

This paper studies that the conductance decrease of distributed lossy material can increase wave lossy and heighten threshold current for the absolute instability and start-oscillation length for the gyro-baekward-wave oscillation. However, the decrease also reduces linear growth rate, axial power and high frequency field gain of gyro-TWT. The paper also shows the design of cylindrical waveguide structure gyro-TWT, using graphite as the distributed lossy material, and the factors are as follows ： electrons current I0 = 10A, interaction length L = 10cm. The result can effectively make a compromise between power, gain and instability suppression, ensuring the stable operation of the gyro-TWT.