基于开槽单矩形栅和圆形电子注的W波段返波振荡器

提出将开槽单矩形栅和圆形电子注作为 W波段返波振荡器的注波互作用回路. 使用 3维电磁场仿真软件CST-MWS对开槽单矩形栅的高频特性进行了仿真分析, 研究结果表明: 相对于传统单矩形栅, 新结构的基模带宽有所展宽; 基模与高次模发生模式竞争的可能性很小; 在采用圆形电子注时新结构能获得大得多的耦合阻抗; 新结构的趋肤损耗略有改善. 将该慢波结构应用于设计一支以94 GHz为频带中心的W 波段返波振荡器: 设计了简洁的慢波过渡部分、输出耦合器和终端匹配衰减器, 优化参数后获得了良好的信号传输特性; 利用粒子模拟软件CST-PS对返波振荡器模型进行了三维大信号注波互作用计算, 设定合适的电子注电流等参数后, 调整工作电压在较宽的频带内获得了瓦级的功率输出, 电子效率在整个频带范围内优于1%. 关键词： 开槽单矩形栅 圆形电子注 返波振荡器 W波段

Design and simulation of W-band BWO based on slotted single-grating and cylindrical beam

A slotted rectangular single-grating with a cylindrical electron beam was proposed as the beam-wave interaction circuit of a W-band backward wave oscillator (BWO). Analysis on the slow-wave characteristics of the structure was done utilizing three-dimensional electromagnetic field simulation software CST-MWS. Results are as follows: The new structure can have a much larger coupling impedance than traditional one; the bandwidth of the fundamental mode can be broadened and the fundamental mode is unlikely to compete with the high-order mode. The loss caused by the skin effect is reduced. The structure was applied to design a W-band backward wave oscillator whose band center is 94 GHz. A simple slow-wave transition part, and the output coupler and terminal matching attenuator were designed, the parameters of which were optimized to obtain good signal transmission. Using CST-PS’s PIC solver, a three-dimensional large-signal particle simulation was done. After setting a suitable electron current and other parameters, watts scale peak output power was obtained within a wide frequency band by adjusting the working voltage, and the electronic efficiency in the band was greater than 1%.
Keywords： slotted rectangular single-grating cylindrical beam back ward wave oscillator W band