高效率曲折槽波导毫米波行波管设计、制造和冷测

Design,fabrication and cold test of a high efficiency folded groove waveguide for w-band sheet beam TWT

本文提出一种适用于工作在毫米波段(85~110 GHz)的带状注高效率曲折槽波导毫米波行波管,并进行了参数优化设计、加工制造和冷测实验研究。曲折槽波导首次采用一次改变周期相速跳变技术提高带状注毫米波行波管电子互作用效率。文中加工制造了三种不同周期个数(包含相速跳变和均匀相速两种类型)的曲折槽波导,并进行了S参数测试,其结果表明应用一次相速跳变技术的曲折槽波导具有良好的传输特性和较宽的带宽。此外,通过测量三种不同周期个数曲折槽波导的相位传输得到了不同周期p_(0)和p_(1)的色散曲线,其结果证明通过仿真得到的色散曲线和测量得到的色散曲线相吻合。文中注波互作用三维粒子模拟结果表明:当曲折槽波导慢波结构末端20个半周期采用一次相速跳变技术时,在频点95 GHz处输出饱和功率达到240 W,比同等条件下的均匀相速曲折槽波导行波管在95 GHz处高70 W。同时,曲折槽波导行波管采用一次相速跳变技术在频带85~110 GHz范围内电子效率明显得到提高,并且在95 GHz处最大电子效率提高了47%。

In this paper,a design,fabrication and cold test of a high efficiency folded groove waveguide(FGW)for w-band(85~110GHz)sheet beam traveling wave tube(TWT)is proposed.One stage phase velocity taper(OSPVT)was used in the FGW to enhance the electronic efficiency of a millimeter-wave sheet beam TWT.The OSPVT was realized via a change of the period of the FGW.Three FGWs with and without OSPVT were fabricat⁃ed and their measured s-parameters demonstrate good transmission characteristics and wide bandwidth.More⁃over,wave dispersions and phase velocities of the unchanged and OSPVT FGWs were obtained from measured transmission phases.3-D particle-in-cell simulations of beam-wave interaction predicted that the proposed TWT with an OSPVT of twenty half periods could output a saturated power of 240 W at 95 GHz,which is about 70 W higher than the case of without OSPVT.Meanwhile,the application of the OSPVT improves the electronic effi⁃ciency in the whole operating frequency range of 85~110 GHz,with a maximum efficiency enhancement of about 47%in the vicinity of 95 GHz.