Ka波段回旋行波管高效率输入耦合器设计  

Design of Ka band gyro-TWT high purity input structure

作　　者：何友辉 胡鹏[2] 陈洪斌[2] He Youhui;Hu Peng;Chen Hongbin(Graduate School of China Academy of Engineering Physics,Mianyang 621900,China;Institute of Applied Electronics,CAEP,Mianyang 621900,China)

机构地区：[1]中国工程物理研究院研究生院,四川绵阳621900 [2]中国工程物理研究院应用电子学研究所,四川绵阳621900

出　　处：《强激光与粒子束》2023年第8期98-105,共8页High Power Laser and Particle Beams

摘　　要：为了实现Ka波段回旋行波管高纯度TE01模式输入,通过在输出口添加滤波结构,对二级功分TE01输入耦合器进行改进,改进后杂散模式传输效率由平均7%下降至2%。该结构主体为一个级联的两级Y型功分网络,能高效地实现矩形波导TE10模式到圆波导TE01模式的转换。在基于传输线理论对功分网络的传输性能理论分析的基础上,借助三维电磁仿真软件进行多次优化迭代,最终得到了一个在31 GHz附近模式转换效率大于99%的宽带TE01输入耦合器,该输入耦合器具有5 GHz的−0.1 dB插入损耗带宽,同时有效频带内的平均模式转换效率高达98.6%,模式纯度在99%以上并且回波损耗小于−15 dB。采用矢量网络分析仪对该器件进行了背靠背冷测实验,结果表明,其带内衰减约为0.5 dB,与仿真计算结果偏差较小,符合工程实际需求。To realize the high-purity TE01 mode input of the Ka-band cyclotron traveling wave tube,the twostage power divider TE01 input coupler is improved by adding a filter structure at the output port,and the transmission efficiency of the spurious mode is reduced from the original average of 7%to less than 2%.The main body of the structure is a cascading two-stage Y-type power divider network,which can efficiently realize the conversion of rectangular waveguide TE10 mode to circular waveguide TE01 mode.Based on the theoretical analysis of transmission performance of power divider network based on transmission line theory,and with the help of 3D electromagnetic simulation software,several optimization iterations are carried out,and finally a wideband TE01 input coupler with mode conversion efficiency greater than 99%near the frequency of 31 GHz is obtained,the input coupling structure has a−0.1 dB insertion loss bandwidth of 5 GHz,and the average mode conversion efficiency in the effective frequency band is as high as 98.6%,the mode purity is 99%and the return loss is less than−15 dB.Back-to-back cold test experiments were carried out on the device using vector network analyzer,and the results show that the in-band attenuation is about 0.5 dB,which deviates little from the simulation calculation result,which meets the actual engineering requirements.

关 键 词：回旋行波管 功分网络 输入耦合结构 高纯度 滤波结构 模式转换 

分 类 号：TN129[电子电信—物理电子学]