X 波段三轴相对论速调管放大器的分析与设计

研究了三轴相对论速调管放大器（TRKA）的模式泄漏和自激振荡问题，对干扰模式的电场分布进行了分析，得知干扰模式在谐振腔中为TM21 模，而在同轴漂移管中耦合为TE21 模。针对干扰模式的传输特点采用在同轴漂移管中加载吸波材料的方式进行抑制，通过三维粒子仿真软件分析了吸波材料的电导率和几何参数对微波吸收的影响，根据仿真分析结果，对同轴漂移管中加载吸波材料的TRKA 结构进行了三维模拟研究，结果表明吸波材料能够很好抑制TRKA 的自激振荡，模拟仿真实现TRKA 输出微波功率1.1GW，效率37%，增益42dB。

Analysis and Design of an X-Band Triaxial Relativistic KlytronAmplifier

In the triaxial relativistic klystron amplifier(TRKA), the mode leakage and the higher order parasitic modeself-oscillation seriously degrade klystron performance, cause pulse shortening. The electric field of the higher mode is exploredin the PIC simulation, the higher mode in resonant cavity is proved to be TM21 mode, which is transformed into TE21 mode incoaxial drift tube. And the microwave attenuating material is introduced to suppress higher mode self-oscillation, the relations ofthe attenuating characteristics with electric conductivity, thickness and length of the attenuating material are studied. Then threedimensional simulation of the X-band TRKA with attenuating material is carried out, and the results show that the introduction ofproper microwave attenuating material can well supress higher mode self-oscillation. We obtain a microwave with power of1.1GW, efficiency of 37%, and gain of 42dB by simulation.