交错双栅带状束行波管的研究与设计
发布时间：2018-11-23 13:10
【摘要】：太赫兹(THz)波是介于微波和红外之间、频率在0.1THz-10THz之间的电磁波。太赫兹波具有:(1)对大多数非金属的介质有着较强的穿透力;(2)太赫兹波的穿透性会随着水和组织密度的改变而改变;(3)相较于X-射线,太赫兹波具有很小的电离性;(4)由于其中心工作频率较高,相对于中心频率较低的器件其绝对带宽具有很大优势;(5)采用太赫兹波作为探测源的器件,得益于较高的频率,通常具有更高的分辨率;(6)相较于红外线,在雨中或者其他恶劣气象条件下,其损耗相对较小等优点。这些优点使得太赫兹波在工业、科研和国防上有着诱人的应用前景。但由于材料科学、研究手段以及精密加工水平等条件的限制,长期以来太赫兹器件的发展极为缓慢,以致于出现了所谓的太赫兹间隙(THz Gap)。近年来材料科学、计算机科学以及精细加工等方面的快速发展,为开展高增益、宽带宽以及小型化的太赫兹器件的研究提供了前提条件,为填补太赫兹间隙,促进太赫兹科学技术的发展奠定了基础。相较于核磁共振与低频段(频率低于100GHz)电子顺磁共振检测技术,太赫兹频段的电子顺磁共振检测仪在分辨率和灵敏度方面具有很大的优势,在医学检测、化学研究以及工业生产中都具有良好的应用前景。但由于中等功率(几十瓦)太赫兹信号源的匮乏,太赫兹频段的电子顺磁共振技术的发展遇到了瓶颈。本论文对带状束器件的交错双栅周期慢波结构、大电子通道宽带耦合器、混合模式输出窗、高电子发射密度带状束电子枪以及周期永磁聚焦磁体等重要部件都进行了探索性的研究;并在相关研究的基础上设计了一支太赫兹波段(263GHz)带状束行波管。论文首先从交错双栅周期慢波结构的色散与耦合阻抗特性的理论出发,深入地研究了这种慢波结构中场分布以及能量储存特性,并在此基础上对通常使用的耦合阻抗进行了修正。结合Pierce小信号增益分析理论、返波振荡分析理论对交错双栅带状束行波管互作用线路的性能进行了总体的评估。在理论分析与仿真模拟的辅助下,为加州大学-戴维斯分校(UC-Davis)260GHz顺磁共振探测系统设计了中心频率为263GHz、工作带宽大于20GHz的太赫兹辐射放大器。模拟结果显示,在19000V、0.15A的带状束驱动下,在工作频带内该真空电子器件可输出50W的功率,实现30dB的增益;且其零驱PIC粒子模拟显示,所设计的带状束行波管有效地抑制了再生振荡与返波振荡的产生,可以稳定的工作。其次本文详细地研究了带状束电子枪以及可调式周期永磁聚焦磁体。分别为200GHz双模带状束行波管与263GHz带状束行波管设计了可调式带状束电子枪与高电流密度电子枪。通过调节横向聚焦极的距离,200GHz可调式电子枪可以发射出0.0866A的低电流带状束来驱动低增益、连续波工作模式的200GHz带状束行波管;也可以产生0.2126A的高电流带状束来驱动200GHz带状束行波管来产生高增益的脉冲电磁辐射。与此同时,在1.2T的均匀磁场的聚焦作用下,低电流带状束与高电流带状束均实现了良好的电子流通率。263GHz带状束电子枪采用了复杂曲面阴极来压缩电子束,来产生高质量的带状束、提高带状束的流通率。与此同时,还对带状束的传输理论进行了分析,研究了带状束的流通性以及其影响因素。在理论分析的基础上,为了约束263GHz带状束电子枪发射出的电子束,本文设计了可调式周期永磁-可调式四极磁体(Permanent Cups Magnet Tunable Quadrupole Magnet,PCM-TQM)。模拟结果显示,即使考虑电磁波对电子束的调制作用与磁块剩磁波动的影响,263GHz带状束电子枪发射的电子束在该聚焦系统的约束下也可实现高达95.85%的热电子传输效率。接着本文详细介绍了带状束行波管的其他相关部件的研究与设计。首先介绍了通过混合模式传输来扩宽传输带宽的盒型窗,并通过S参数仿真以及热分析两方面来验证了该设计的可行性。为了降低高频率电磁波在传统波导传输线路上的损耗,本文为260GHz顺磁共振系统设计了低损耗、高纯度的波纹波导远距离传输系统。最后,根据带状束的特点为263GHz带状束行波管设计了相应的电子收集系统。通过尾端引导磁体的引入、椭圆形收集极的采用,新的收集系统大大缩短了带状束收集系统的长度,提高了电子的收集效率。本文的最后给出了部分前文所设计的器件的加工实物与测试结果。测试结果验证了前面的部分设计,并为进一步改进设计、修正加工误差指引了方向。
[Abstract]:The terahertz (THz) wave is an electromagnetic wave between the microwave and the infrared and the frequency is between 0. 1THz and 10THz. The terahertz wave has the advantages that: (1) the medium with most non-metals has a strong penetrating power; (2) the penetration of the terahertz wave can be changed with the change of water and tissue density; (3) the phase is smaller than that of the X-ray and the terahertz wave has very little ionicity; (4) due to its high center operating frequency, the absolute bandwidth of the device with a lower center frequency has a great advantage; (5) a device employing a terahertz wave as a source of detection benefits from a higher frequency, typically having a higher resolution; (6) the phase is less than infrared, The loss is relatively small in the rain or in other severe weather conditions. These advantages make the terahertz wave attractive for industrial, scientific research and national defense. The so-called Terahertz Gap (THz Gap) has been developed for a long time due to the limitations of materials science, research methods, and precision processing levels. In recent years, the rapid development of the material science, computer science and fine processing has provided a prerequisite for the research of the terahertz device with high gain, wide bandwidth and miniaturization, and lays a foundation for the development of the terahertz science and technology to fill the terahertz gap. Compared with the electronic paramagnetic resonance detection technology of the nuclear magnetic resonance and low-frequency section (frequency lower than 100GHz), the electronic paramagnetic resonance detector in the terahertz frequency band has a great advantage in terms of resolution and sensitivity, and has good application prospect in medical detection, chemical research and industrial production. However, due to the lack of the medium power (tens of watts) of the terahertz signal source, the development of the terahertz frequency band has encountered a bottleneck. This paper makes an exploratory study on the staggered double-grid periodic slow wave structure, the large electronic channel wide band coupler, the mixed mode output window, the high electron emission density ribbon beam electron gun and the periodic permanent magnet focusing magnet of the ribbon beam device. A terahertz band (263GHz) band-beam traveling wave tube is designed on the basis of the relevant research. In this paper, based on the theory of the dispersion and the coupling impedance of the slow-wave structure of the staggered double-gate period, the field distribution and the energy storage characteristics of the slow-wave structure are studied in-depth, and the commonly used coupling impedance is modified. In this paper, the performance of the cross-acting line of the staggered double-grid band-beam traveling-wave tube is evaluated by the theory of the small-signal gain analysis and the back-wave oscillation analysis. Under the aid of theoretical analysis and simulation simulation, a terahertz radiation amplifier with a center frequency of 263GHz and a working bandwidth of more than 20GHz is designed for the UC-Davis 260GHz paramagnetic resonance detection system. The simulation results show that in the band-shaped beam drive of 19000V, 0. 15A, the power of 50W can be output by the vacuum electronic device in the working frequency band, and the gain of 30dB can be realized; and the zero-drive PIC particle simulation shows that the designed band-shaped beam-wave tube effectively suppresses the generation of the regenerative oscillation and the return wave oscillation, a stable operation. Secondly, the beam-beam electron gun and the adjustable periodic permanent-magnet focusing magnet are studied in detail. An adjustable band-beam electron gun and an electron gun with high current density are designed for a 200GHz dual-mode ribbon-beam traveling-wave tube and a 263GHz band-beam traveling-wave tube. by adjusting the distance of the transverse focusing electrode, the 200GHz adjustable electron gun can emit a low-current band-shaped beam of 0.86A to drive a 200GHz band-shaped beam traveling wave tube with a low gain and a continuous wave working mode; a high current band beam of 0. 2126a can also be produced to drive a 200ghz band-beam traveling wave tube to generate high gain pulsed electromagnetic radiation. At the same time, under the focus of a uniform magnetic field of 1. 2T, a good electron flow rate is achieved for both the low current ribbon beam and the high current ribbon beam. The 263GHz band beam electron gun uses a complex curved cathode to compress the electron beam to produce a high-quality ribbon beam and improve the flow rate of the ribbon beam. At the same time, the transmission theory of the ribbon beam is analyzed, the circulation of the ribbon beam and its influencing factors are studied. 鍦ㄧ悊璁哄垎鏋愮殑鍩虹涓，
本文编号：2351728
[Abstract]:The terahertz (THz) wave is an electromagnetic wave between the microwave and the infrared and the frequency is between 0. 1THz and 10THz. The terahertz wave has the advantages that: (1) the medium with most non-metals has a strong penetrating power; (2) the penetration of the terahertz wave can be changed with the change of water and tissue density; (3) the phase is smaller than that of the X-ray and the terahertz wave has very little ionicity; (4) due to its high center operating frequency, the absolute bandwidth of the device with a lower center frequency has a great advantage; (5) a device employing a terahertz wave as a source of detection benefits from a higher frequency, typically having a higher resolution; (6) the phase is less than infrared, The loss is relatively small in the rain or in other severe weather conditions. These advantages make the terahertz wave attractive for industrial, scientific research and national defense. The so-called Terahertz Gap (THz Gap) has been developed for a long time due to the limitations of materials science, research methods, and precision processing levels. In recent years, the rapid development of the material science, computer science and fine processing has provided a prerequisite for the research of the terahertz device with high gain, wide bandwidth and miniaturization, and lays a foundation for the development of the terahertz science and technology to fill the terahertz gap. Compared with the electronic paramagnetic resonance detection technology of the nuclear magnetic resonance and low-frequency section (frequency lower than 100GHz), the electronic paramagnetic resonance detector in the terahertz frequency band has a great advantage in terms of resolution and sensitivity, and has good application prospect in medical detection, chemical research and industrial production. However, due to the lack of the medium power (tens of watts) of the terahertz signal source, the development of the terahertz frequency band has encountered a bottleneck. This paper makes an exploratory study on the staggered double-grid periodic slow wave structure, the large electronic channel wide band coupler, the mixed mode output window, the high electron emission density ribbon beam electron gun and the periodic permanent magnet focusing magnet of the ribbon beam device. A terahertz band (263GHz) band-beam traveling wave tube is designed on the basis of the relevant research. In this paper, based on the theory of the dispersion and the coupling impedance of the slow-wave structure of the staggered double-gate period, the field distribution and the energy storage characteristics of the slow-wave structure are studied in-depth, and the commonly used coupling impedance is modified. In this paper, the performance of the cross-acting line of the staggered double-grid band-beam traveling-wave tube is evaluated by the theory of the small-signal gain analysis and the back-wave oscillation analysis. Under the aid of theoretical analysis and simulation simulation, a terahertz radiation amplifier with a center frequency of 263GHz and a working bandwidth of more than 20GHz is designed for the UC-Davis 260GHz paramagnetic resonance detection system. The simulation results show that in the band-shaped beam drive of 19000V, 0. 15A, the power of 50W can be output by the vacuum electronic device in the working frequency band, and the gain of 30dB can be realized; and the zero-drive PIC particle simulation shows that the designed band-shaped beam-wave tube effectively suppresses the generation of the regenerative oscillation and the return wave oscillation, a stable operation. Secondly, the beam-beam electron gun and the adjustable periodic permanent-magnet focusing magnet are studied in detail. An adjustable band-beam electron gun and an electron gun with high current density are designed for a 200GHz dual-mode ribbon-beam traveling-wave tube and a 263GHz band-beam traveling-wave tube. by adjusting the distance of the transverse focusing electrode, the 200GHz adjustable electron gun can emit a low-current band-shaped beam of 0.86A to drive a 200GHz band-shaped beam traveling wave tube with a low gain and a continuous wave working mode; a high current band beam of 0. 2126a can also be produced to drive a 200ghz band-beam traveling wave tube to generate high gain pulsed electromagnetic radiation. At the same time, under the focus of a uniform magnetic field of 1. 2T, a good electron flow rate is achieved for both the low current ribbon beam and the high current ribbon beam. The 263GHz band beam electron gun uses a complex curved cathode to compress the electron beam to produce a high-quality ribbon beam and improve the flow rate of the ribbon beam. At the same time, the transmission theory of the ribbon beam is analyzed, the circulation of the ribbon beam and its influencing factors are studied. 鍦ㄧ悊璁哄垎鏋愮殑鍩虹涓，
本文编号：2351728
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