由于非线性计算特别是场相位方面缺乏专门的分析工具及方法,一直难以对折叠波导行波管的电子效率及副特性进行准确分析。通过CST PARTICLE STUDIO的PIC仿真模块,利用行波管注波互作用中的轴向基波电流与轴向基波电场的相位差表征注波相位关系,提出了一种相位分析方法。通过比较V波段折叠波导行波管单跳变周期结构与均匀周期结构的注波互作用模拟结果,揭示了注波互作用中相位聚焦的物理机理,优化后电子效率提高了5.13%,验证了PIC模拟中相位分析方法的合理性。 Due to the lack of specialized analytical tools and methods for non-linear calculations, especially field phases, it has been difficult to accurately analyze the electron-efficiency and side-properties of folded waveguide TWTs. By the PIC simulation module of CST PARTICLE STUDIO, a phase analysis method is proposed by using the phase difference between the axial fundamental current and the axial fundamental electric field in the wave-tube interaction. The physical mechanism of phase focusing in the interaction of wavelets is revealed by comparing the simulation results of the wave-slip interaction between the single-transition structure and the uniform periodic structure of the folded waveguides. The optimized electron efficiency is improved by 5.13% Rationality of Phase Analysis in PIC Simulation.