W波段大功率集成极靴式互作用结构研究

Study of W-band High-Power Integrated Pole Piece Interaction Structure

针对W波段大功率折叠波导行波管的技术难点,提出了一种一体式加工的集成极靴式互作用结构,该结构将直角型折叠波导嵌入到极靴中,实现注-波互作用结构与聚焦系统的集成,提高周期永磁系统的聚焦能力,再通过增加阴极发射的电子注电流,实现功率的提升。文中首先介绍了集成极靴式互作用结构,提供该结构中慢波结构的尺寸参数,计算其色散特性及耦合阻抗曲线,并设计了相应的磁聚焦系统。最终对互作用结构进行仿真模拟,在90~100 GHz频带内可获得高于700 W的饱和输出功率。带内饱和增益均小于20 dB,可有效防止自激振荡的产生,该互作用结构可广泛应用于级联功率放大模块的后级放大器中。

Aiming at the technical problem of high power folded waveguide(FWG)traveling wave tube(TWT),this paper proposes an integrated pole piece interaction structure.This structure combines the right-angle bend FWG slow-wave structure(SWS)with the periodic permanent magnet focusing system by integral machining to improve the focusing ability of periodic permanent magnet(PPM),and the high output power is achieved by increasing the electron beam current emitted by cathode.In this paper,the overall manufacturing process is first introduced as well as the parameters of W-band FWG slow-wave structure.Then,the integrated pole piece interaction system is designed based on the parameters of FWG and the design is proved to be feasible by PIC simulation.Finally,the saturated output power of over 700 W is obtained in a frequency range of 90-100 GHz.The saturated gain in the frequency range is less than 20 dB which can prevent the generation of self-oscillation effectively.This interaction structure can be widely used in the last stage amplifier of the cascade amplifier module.