基于金属线慢波结构的太赫兹返波振荡器

发布时间：2018-04-30 23:38

本文选题：太赫兹 + 返波管　；参考：《电子科技大学》2017年硕士论文

【摘要】：太赫兹(Teraherz)辐射指的是频率在0.1~10THz范围内的电磁波辐射,其波长的范围是3um~3mm,从频谱上看,太赫兹辐射波在毫米波和红外线,大于无线电波频率,小于光波的频率。作为一种新兴的前沿科学,太赫兹技术已经应用在安全检查、环境监测、航空航天、太赫兹通信、无损检测、材料科学和医学成像等许多领域,受到世界各国科学家的广泛重视。作为利用太赫兹技术的先决条件,就是能稳定和有效的产生太赫兹信号,这个条件是限制太赫兹器件发展的关键因素。目前,返波管,也被称为返波振荡器,被认为是产生太赫兹波最有前景的真空器件,具有可以小型化、宽电子调谐、造价低的特点。而慢波结构是返波振荡器中最核心的部分,它的主要功能是交换电子束中电子和电磁场中的能量,是影响返波管性能好坏和各项参数的重要部分。因此,一种合适的互作用慢波结构对于返波管的高频振荡系统来说至关重要。本文主要设计了一种拥有新型金属绕线慢波结构的返波振荡器,使其工作在0.3THz频段,使其在整体上具有结构新颖、低造价、容易组装的特点,在性能上具有高输出功率、高耦合阻抗、低工作电压和低工作电流密度等特点。本文也详细介绍了该结构的设计过程。为了体现该绕线返波管良好的性能,本文中还设计了返波管的输出和匹配结构,之后利用3-D电磁仿真模拟软件CST(Computer Simulation Technology)对整体结构进行仿真,并通过优化得到了最优的冷腔和热腔的测试参数。在冷腔仿真方面,得到了色散曲线、耦合阻抗、电场大小和分布、S参数等参数,在热腔方面,得到了输出功率、能量变化过程等参数。另外,该返波管还可以适用于不同的电子发射方式,例如传统的热阴极电子枪和赝火花放电产生电子的方式,分析了不同的电流密度对输出功率的影响。最后,当工作电压为1.2kV,工作电流密度是94A/cm2,电流幅值大小为50mA的电条件时,这种拥有新型的绕线慢波结构的返波管可以得到输出功率大于154mW,工作频率在335GHz,电子调谐带宽超过24GHz的结果。该研究成果对于太赫兹源器件结构种类的扩展具有潜在的应用价值。
[Abstract]:Teraherz radiation refers to the electromagnetic wave radiation with a frequency in the range of 0.1~10THz, the wavelength of which is 3 mm or 3 mm. From the spectrum, the terahertz radiation is larger than the frequency of radio wave and less than the frequency of light wave in millimeter wave and infrared ray. As a new frontier science, terahertz technology has been used in many fields, such as safety inspection, environmental monitoring, aerospace, terahertz communication, nondestructive testing, material science and medical imaging, etc. Scientists from all over the world attach great importance to it. As a prerequisite for the use of terahertz technology, it is necessary to produce terahertz signals stably and efficiently. This condition is a key factor limiting the development of terahertz devices. At present, the backwave tube, also known as the backwave oscillator, is considered to be the most promising vacuum device for the generation of terahertz wave. It has the characteristics of miniaturization, wide electron tuning and low cost. The slow wave structure is the core part of the backwave oscillator. Its main function is to exchange the energy in the electron beam and the electromagnetic field. It is an important part that affects the performance and the parameters of the backwave oscillator. Therefore, a suitable interaction slow wave structure is very important for the high frequency oscillation system of the backwave tube. In this paper, a kind of backwave oscillator with a new metal winding slow wave structure is designed to work in the 0.3THz band, which has the characteristics of novel structure, low cost, easy assembly, and high output power in performance. High coupling impedance, low working voltage and low working current density. This paper also introduces the design process of the structure in detail. In order to show the good performance, the output and matching structure of the backward-wave tube is designed, and then the whole structure is simulated by 3-D electromagnetic simulation software CST(Computer Simulation Technology. The optimum parameters of cold cavity and hot cavity are obtained by optimization. In cold cavity simulation, the parameters such as dispersion curve, coupling impedance, electric field size and distribution S parameters are obtained. In thermal cavity, the parameters such as output power and energy change process are obtained. In addition, it can be applied to different electron emission modes, such as the traditional hot cathode electron gun and pseudo-spark discharge, and the influence of different current density on the output power is analyzed. Finally, when the working voltage is 1.2 kV, the working current density is 94 A / cm ~ 2 and the current amplitude is 50mA, The output power is greater than 154mW, the operating frequency is 335GHz, and the electronic tuning bandwidth is higher than 24GHz. The research results have potential application value for the extension of terahertz source devices.
【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN752;TN125

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