回旋行波管多模振荡研究

发布时间：2018-09-04 06:25

【摘要】：回旋行波管是一种相对论非线性真空电子器件,其在微波毫米波以及太赫兹波段有不可替代的优势。其结构简单、输出功率高、增益高、工作频率高、带宽宽等优点使得其很适合应用于雷达、通信、电子对抗、等离子体加热等高频高能领域。回旋行波管的高频结构是回旋行波管的核心部件之一,它是电子注与高频电磁波发生互作用的主要场所,也是实现电子注与电磁波能量转换的主要场所。然而,由于其采用横向互作用机理,高频结构中很容易发生竞争模式振荡,限制回旋行波管的性能。因此,许多科研人员致力于回旋行波管多模振荡的研究,从理论和实践上发展出多种方法来抑制回旋行波管的多模振荡,提高回旋行波管的工作性能。其中在高频结构中采用介质加载是一种使用广泛、成熟有效的方法。本文对回旋行波管的多模振荡的理论和种类进行讨论,通过对圆波导多模叠加的场方程和回旋电子运动方程联立推导,得到回旋行波管多模互作用方程组。同时分析回旋行波管中多种自激振荡的原理和影响因素,考虑抑制方法。并且开发适用于回旋行波管的蚁群分裂算法,通过数值优化算法对回旋行波管的高频结构进行仿真优化,设计出一种W波段的分布式介质回旋行波管高频结构,其输出功率达到136.63kW,效率达到28.46%,饱和增益达到51.36dB,带宽达到7GHz。本文的主要研究工作有:1.在回旋行波管自洽非线性理论中考虑多模效应,分析多模互作用的电磁波分布和电子注运动方程,对其进行联立推导,得到多模互作用方程组。2.对回旋行波管中自激振荡的种类进行讨论,分析其产生机理、影响因素和介质加载方法对其的抑制。并定性地分析端口反射带来的反射振荡。3.针对回旋行波管的实际问题在蚁群算法的基础上发展出蚁群分裂算法,编写优化算法程序,对回旋行波管高频结构进行优化设计。4.通过Particl-in-cell(PIC)粒子模拟得到一性能良好的W波段介质加载回旋管高频结构的仿真结果,并对仿真结果进行分析。
[Abstract]:Cyclotron is a kind of relativistic nonlinear vacuum electronic device which has irreplaceable advantages in microwave millimeter wave and terahertz wave band. Because of its simple structure, high output power, high gain, high operating frequency and wide bandwidth, it is suitable for high frequency and high energy fields such as radar, communication, electronic countermeasure, plasma heating and so on. The high frequency structure of the gyrotron is one of the core components of the gyrotron. It is the main place where the electron beam interacts with the high frequency electromagnetic wave, and also the main place to realize the energy conversion between the electron beam and the electromagnetic wave. However, due to the transverse interaction mechanism, the competitive mode oscillation is easy to occur in the high frequency structure, which limits the performance of the gyrotron. Therefore, many researchers devote themselves to the study of the gyrotron multimode oscillation, and develop many methods to suppress the gyrotron multimode oscillation and improve the performance of the gyrotron. The application of dielectric loading in high frequency structure is a widely used, mature and effective method. In this paper, the theory and types of multimode oscillations in gyrotron traveling wave tube are discussed. The equations of multimode interaction of cyclotron traveling wave tube are derived by simultaneous derivation of field equation and cyclotron motion equation of multimode superposition of circular waveguide. At the same time, the principle and influence factors of various self-excited oscillations in gyrotron TWT are analyzed, and the suppression method is considered. An ant colony splitting algorithm suitable for gyrotron is developed. The high frequency structure of gyrotron TWT is simulated and optimized by numerical optimization algorithm, and a W-band distributed medium gyrotron TWT high frequency structure is designed. The output power is 136.63kW, the efficiency is 28.46kW, the saturation gain is 51.36dB, the bandwidth is 7GHz. The main research work of this paper is: 1. Considering the multimode effect in the self-consistent nonlinear theory of gyrotron traveling wave tube, the electromagnetic wave distribution and the equation of electron beam motion of the multimode interaction are analyzed, and the equations of multimode interaction. The types of self-excited oscillations in gyrotron traveling wave tube are discussed. The mechanism of the oscillation is analyzed. The influence factors and the method of medium loading to suppress the oscillation are analyzed. The reflection oscillation caused by port reflection is analyzed qualitatively. Aiming at the practical problem of gyrotron, an ant colony splitting algorithm is developed based on ant colony algorithm, and an optimization algorithm program is written to optimize the high frequency structure of gyrotron. 4. The simulation results of a W-band dielectric loaded gyrotron high frequency structure with good performance are obtained by Particl-in-cell (PIC) particle simulation, and the simulation results are analyzed.
【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】：TN124

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