变周期大结构低压工作折叠波导行波管的理论与模拟研究

为解决工作在3 mm波段及以上频段的折叠波导行波管因加工精度和功率容量的局限性, 提出了非渐变型有限变周期折叠波导慢波结构. 首先给出了这种结构能够有效增大高次空间谐波耦合阻抗的理论基础, 并导出了色散和耦合阻抗表达式; 然后进行数值计算, 给出一组优化后的设计参数, 并以此确定行波管的工作点; 最后利用MAFIA粒子模拟软件进行大信号互作用模拟, 获得有效增益. 在结构和周期都比较大的情况下, 实现了相对工作电压比较低的行波管设计. 关键词： 折叠波导 变周期 高次模式 行波管

Theory and simulation of the folded waveguide traveling-wave tube working in low voltage with changed period and big size

The folded waveguide traveling-wave tube which works at 3 mm band and above the band is limited to machining accuracy and power capacity. So a slow-wave folded waveguide structure which has a finite number of cycles and whose period can be changed nonasymptotically is proposed. Firstly, the theory for effectively increasing the high-order space harmonic coupling impedance of the structure is given. And the expressions for dispersion and coupling impedance are derived. Then through the simulation, a set of optimized design parameters is achieved. Thus the operating point of the traveling-wave tube is determined. Finally, it is simulated by MAFIA. And an effective gain is obtained. The traveling-wave tube which works at low voltage, relatively large size and relatively large period, is designed.