中文摘要：

本文根据四腔强流相对论速调管设计过程中出现的高次模振荡现象,采用电磁场软件模拟,分析了这种振荡的产生原因,给出抑制这种高次模振荡的方法.利用二维和三维模拟软件,研究了谐振腔谐振频率、谐振腔Q值、漂移管长度、特性阻抗等参数的变化对高次模振荡的影响,模拟上验证了高次模振荡抑制方法的有效性,并在输出端模拟获得了功率2.13 GW、效率26%、增益60 dB的输出微波,实现了2D,3D中高次模振荡的有效抑制.最终在实验中获得了功率1.9 GW、效率24%、增益61 dB的输出微波.

英文摘要：

This paper described a high-order mode oscillation phenomenon,in the simulation of four-cavity intense relativistic klystron amplifer（IRKA）.And we have analyzed the cause of this kind of oscillation,and explored the suppression methods for the whole tube.Two-dimensional and three-dimensional electromagnetism simulation software are used to study the infuence of parameter＇s changes（such as the oscillation frequency of cavities,the cavity Q value,the length of drift tube,and the characteristic impedance） on the high-order mode oscillation.The efectiveness of the high-order mode oscillation suppression methods is verifed by simulation.Then,by optimizing the structure of IRKA,we have achieved an output microwave with a power of 2.13 GW,a gain of 60 dB and an efciency of 26 % in simulation,and the high-mode oscillation is avoided efectively.Finally,an output microwave with a power of 1.9 GW,a gain of 61 dB,and an efciency of 24 % is gained in the experiment.