多间隙耦合腔的电磁仿真与设计

发布时间：2018-01-27 16:44

本文关键词： 多间隙耦合腔谐振频率特性阻抗模式重叠稳定性　出处：《北方工业大学》2017年硕士论文　论文类型：学位论文

【摘要】：分布互作用速调管是在传统速调管中引入多间隙耦合腔,分布互作用速调管更容易在高频段获得更大的输出功率、增益和带宽能够满足现代设备的需求。多间隙耦合腔是分布互作用速调管发展的一项关键技术。本文围绕多间隙耦合腔电磁仿真与设计这一重要主题,基于现有等效电路、微波网络基本原理和空间电荷波基本理论,运用三维电磁仿真软件围绕耦合腔中谐振频率、特性阻抗、模式重叠及其稳定性展开理论分析和数值模拟,主要开展了以下几方面的工作:1.从微波网络基本原理出发,结合谐振腔等效电路的研究方法,得到了多间隙耦合腔等效电路基本模型。以三间隙休斯结构耦合腔为例,分析三间隙休斯结构耦合腔各个模式谐振频率及其特性阻抗随耦合槽谐振频率和耦合系数变化规律。2.运用三维电磁仿真软件,通过调整耦合槽结构尺寸及其位置,计算各个模式谐振频率及其对应特性阻抗,结果发现耦合槽角度对于模式频率分布及其特性阻抗数值起着主导作用,耦合槽位置对各个模式特性阻抗影响较大,耦合槽宽度主要影响各个模式谐振频率的间隔大小。3.结合耦合腔中不同模式的冷参特性与结构尺寸变化规律,从谐振频率和特性阻抗角度出发,最终优化得到在耦合角度在105°,前三个模式(-π模、-π/2模、2π模)重叠,耦合角度在225°后三个模式(π模、π/2模、2π模)重叠状态,对应特性阻抗幅值相对较大。4.基于空间电荷波理论得到多间隙耦合腔电子注电导的计算公式,根据三维电磁仿真软件得到三间隙休斯结构耦合腔中各个模式的特性阻抗,通过计算各个模式电子注的品质因数倒数,在三间隙耦合腔在两种多模式重叠前提下,分析了各个模式的随直流电压变化曲线,指出注-波同步作用是实现其稳定工作的关键因素,选择工作电压20kV可以实现三个工作模式稳定工作,寄生模式也容易得到抑制。
[Abstract]:The distributed interaction klystron is a multi-gap coupling cavity introduced into the traditional klystron. It is easier for the distributed interaction klystron to obtain more output power in the high frequency band. Gain and bandwidth can meet the needs of modern equipment. Multi-gap coupled cavity is a key technology in the development of distributed interaction klystron. This paper focuses on the electromagnetic simulation and design of multi-gap coupled cavity. Based on the existing equivalent circuit, microwave network principle and space charge wave theory, the resonant frequency and characteristic impedance in the coupling cavity are simulated by three-dimensional electromagnetic simulation software. The theoretical analysis and numerical simulation of mode overlap and its stability are mainly carried out in the following aspects: 1. Starting from the basic principle of microwave network and combining with the research method of resonant cavity equivalent circuit. The equivalent circuit model of multi-gap coupled cavity is obtained. The three-gap Hughes structure coupling cavity is taken as an example. The resonant frequency and characteristic impedance of the three-gap Hughes structure coupled cavity are analyzed with the change of resonant frequency and coupling coefficient. 2. Three-dimensional electromagnetic simulation software is used to simulate the resonant frequency and the characteristic impedance of the coupling cavity. By adjusting the structure size and position of the coupling slot, the resonant frequency and its corresponding characteristic impedance of each mode are calculated. The results show that the angle of the coupling slot plays a leading role in the mode frequency distribution and the value of the characteristic impedance. The coupling slot position has a great influence on the impedance of each mode, and the width of the coupling slot mainly affects the interval between the resonant frequencies of each mode. 3. Combining the cold parameter characteristics of different modes in the coupling cavity and the variation of structure size. From the angle of resonant frequency and characteristic impedance, it is finally optimized that the first three modes are overlapped at 105 掳and the first three modes-蟺 / 2 mode / 2 蟺 mode). The three modes (蟺 mode, 蟺 / 2 mode and 2 蟺 mode) overlap at 225 掳. The corresponding characteristic impedance amplitude is relatively large. 4. Based on the space charge wave theory, the formula for calculating the electron beam conductance of multi-gap coupled cavity is obtained. According to the three-dimensional electromagnetic simulation software, the characteristic impedance of each mode in the three-gap Hughes structure coupling cavity is obtained, and the inverse of the quality factor of each mode electron beam is calculated. Under the premise of two kinds of multi-mode overlap, the curves of each mode with DC voltage are analyzed, and it is pointed out that the synchronous beam-wave action is the key factor to realize the stability of the cavity. The operation voltage of 20kV can work stably in three modes, and the parasitic mode can be easily suppressed.
【学位授予单位】：北方工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN122

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