W波段共焦波导回旋行波管高频结构研究

发布时间：2018-01-03 16:27

本文关键词：W波段共焦波导回旋行波管高频结构研究　出处：《电子科技大学》2016年硕士论文　论文类型：学位论文

【摘要】：毫米波技术在高能武器、宇宙探测、雷达跟踪、电子对抗和气象预报等领域具有非常重要的应用。而毫米波源是整个毫米波技术的重点和难点,因此对毫米波源的研究非常重要。回旋行波管是一种基于电子回旋脉塞机理工作的电真空器件,由于其在毫米波乃至太赫兹频段可以得到宽带宽、高效率和高功率的输出信号,已经成为国内外的研究热点。但是随着频段的升高,回旋行波管的模式竞争问题越来越突出,因此那些具有模式选择特性的高频结构就脱颖而出。共焦波导是一种横向开敞的结构,电磁波可以从横向开敞面衍射出去,且不同模式的衍射损耗不同,因此具有模式选择作用,这种模式选择特性可以用来解决模式竞争问题。本文进行了W波段共焦波导回旋行波管高频结构的研究。经过对模式竞争和功率容量的折中,确定工作模式为HE06。从回旋行波管的线性理论入手,对共焦波导回旋行波管高频结构的色散特性和衍射损耗进行理论计算和仿真验证,同时也分析了其模式竞争问题。本文还进行了共焦波导回旋行波管输入耦合系统的研究,从传统的单端垂直输入耦合系统和双端垂直对称输入耦合系统入手,提出了一种倾斜对称输入的方法来扩展输入耦合系统的带宽。同时提出了通过改变边界条件来抑制竞争模式的耦合。最后对共焦波导输入耦合系统进行了仿真优化,该输入耦合系统的性能:最大耦合效率为75.68%,3 dB耦合带宽为8.2 GHz,相对带宽为8.41%,耦合效率大于等于60%的带宽为6.8 GHz的。最后基于回旋行波管非线性理论,对回旋行波管中注-波互作用的机理进行分析。对工作模式为HE06的共焦波导进行PIC仿真,发现其模式竞争问题非常严重,导致工作模式信号不能高效、稳定的放大。从减小竞争模式数量的角度出发,并且为了消除输入耦合器导致的问题,设计了工作模式为HE04的共焦波导,采用直接输入的方式对其进行了PIC仿真计算和优化,得到200 kW的稳定输出功率,最大输出功率是204 kW。
[Abstract]:Millimeter-wave technology has very important applications in the fields of high-energy weapons, space exploration, radar tracking, electronic countermeasure and weather forecast, etc. The millimeter wave source is the focus and difficulty of the whole millimeter wave technology. Therefore, the study of millimeter wave source is very important. Gyrotron traveling wave tube is an electronic vacuum device based on electron cyclotron maser mechanism, because it can get wide band in millimeter wave and even terahertz band. High efficiency and high power output signal has become a research hotspot at home and abroad, but with the rise of frequency band, the mode competition problem of gyrotron TWT becomes more and more prominent. The confocal waveguide is a kind of transverse open structure, electromagnetic wave can be diffracted from the transverse open surface, and the diffractive loss of different modes is different. Therefore, it has the role of mode selection. This mode selection characteristic can be used to solve the problem of mode competition. In this paper, the high-frequency structure of W-band confocal waveguide cyclotron traveling wave tube is studied. The trade-off between mode competition and power capacity is given. Based on the linear theory of cyclotron, the dispersion characteristics and diffraction loss of high frequency structure of confocal waveguide gyrotron are calculated and verified by simulation. At the same time, the mode competition problem is also analyzed. In this paper, the input coupling system of confocal waveguide cyclotron traveling wave tube is studied, starting with the traditional single-ended vertical input coupling system and the two-terminal vertical symmetric input coupling system. A skew symmetric input method is proposed to expand the bandwidth of the input coupling system. At the same time, the competitive mode coupling is restrained by changing the boundary conditions. Finally, the simulation of the confocal waveguide input coupling system is carried out. Turn. The performance of the input coupling system: the maximum coupling efficiency is 75.68 dB coupling bandwidth is 8.2GHz, the relative bandwidth is 8.41%. The coupling efficiency is greater than 60% and the bandwidth is 6.8 GHz. Finally, based on the nonlinear theory of cyclotron. The mechanism of beam-wave interaction in gyrotron traveling wave tube is analyzed. The PIC simulation of a confocal waveguide operating in HE06 mode shows that the mode competition problem is very serious. In order to reduce the number of competing modes and eliminate the problem caused by the input coupler, a confocal waveguide with HE04 mode is designed. The direct input method is used to simulate and optimize the output power of 200kW, and the maximum output power is 204kW.
【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TN124

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