利用半绝缘砷化镓体雪崩产生高压高重频纳秒电脉冲的研究

发布时间：2018-03-14 06:22

  本文选题：高重频脉冲　切入点：深能级　出处：《西安理工大学》2017年硕士论文　论文类型：学位论文

【摘要】：脉冲功率技术是利用开关或储能器件对一定时间宽度的能量进行压缩,输出高功率短脉冲的技术。因此,如何提高输出脉冲的功率和压缩脉宽是脉冲功率技术的关键。开关技术是脉冲功率技术的关键环节,高重复频率、全固态和小型化是当前开关技术的主流发展趋势。基于GaAs光电导开关非线性延迟模式的实验现象,我们提出了利用雪崩触发半绝缘GaAs导通的研究思路。利用雪崩触发半绝缘GaAs导通,能够让GaAs光电导开关摆脱激光限制,实现一种新型的高压雪崩管。通过对电极形状的优化设计,我们在半绝缘GaAs材料上制作非对称尖端电极,形成实验样品。实验表明这种样品能够利用直接施加高压,局部雪崩的方式触发导通。导通后半绝缘GaAs样品能够像光电导开关非线性模式一样持续导通,并伴随样品电场锁定。在此基础上,论文开展了利用半绝缘GaAs体雪崩产生高重频纳秒脉冲的实验研究,完成了以下工作:1.在半绝缘GaAs样品上制备非对称电极形成实验样品。在对样品的静态伏安特性测定的基础上,利用电容储能测试电路,测试了体雪崩样品脉冲输出特性,产生了脉冲宽度为5.5ns,1.9kV的单发高压电脉冲。2.根据半绝缘GaAs体雪崩样品的伏安特性,设计了基于高压交流电源的高重频运行实验方案,开展了雪崩样品在交流电源下的重频实验研究。在两种不同的供电模式中,分别产生了脉冲宽度493.8ns,幅值5.92kV,频率52.2kHz和脉宽243ns,幅值4.39kV,频率40kHz的电脉冲。3.测定了高温下GaAs雪崩样品的伏安特性,发现高温下样品呈现显著的电流控制型负阻特性。与室温下的伏安特性不同的是,高温下样品电场锁定特性消失,无论是升压过程还是降压过程,样品均表现出负阻特性,其负阻数值随温度升高而降低,在70℃时高达2.4MΩ。根据样品表现出的高温负阻特性,解释了高重频模式下电流尖峰的形成机理。半绝缘GaAs体雪崩产生重频脉冲,是一种新型产生高重频脉冲的方法,有望以雪崩的模式,实现几十kHz高压纳秒重频脉冲。对半绝缘GaAs体雪崩现象的深入研究将为固态开关领域注入新活力。
[Abstract]:Pulse power technology is the technology that uses switch or energy storage device to compress the energy of certain time width and output high power short pulse. How to increase the output pulse power and compression pulse width is the key of pulse power technology, switch technology is the key link of pulse power technology, high repetition rate, All solid state and miniaturization are the main trend of switch technology. Based on the experimental phenomenon of nonlinear delay mode of GaAs photoconductive switch, We put forward the idea of using avalanche to trigger semi-insulating GaAs conduction. By using avalanche to trigger semi-insulating GaAs conduction, the GaAs photoconductive switch can get rid of laser limitation. A new type of high voltage avalanche tube is realized. By optimizing the shape of the electrode, we fabricate the asymmetric tip electrode on the semi-insulating GaAs material and form the experimental sample. The experiment shows that this kind of sample can be directly applied to the high voltage. The local avalanche triggers the conduction. The semi-insulating GaAs sample after conduction can be continuously switched on like the nonlinear mode of the photoconductive switch, with the sample electric field locked. On this basis, In this paper, an experimental study on the generation of nanosecond pulse with high repetition frequency by using semi-insulating GaAs body avalanche has been carried out. The following work has been done: 1. The asymmetric electrode was prepared on the semi-insulating GaAs sample to form the experimental sample. Based on the determination of the static voltammetric characteristics of the sample, The pulse output characteristics of bulk avalanche samples were tested by using the capacitance energy storage test circuit. The pulse width of 5.5nsL 1.9kV single high-voltage electric pulse was obtained. According to the volt-ampere characteristics of semi-insulating GaAs body avalanche samples, The experimental scheme of high repetition frequency operation based on high voltage AC power supply is designed, and the experimental research on the repetition rate of avalanche sample under AC power supply is carried out. In two different power supply modes, The pulse width is 493.8ns, the amplitude is 5.92kV, the frequency is 52.2 kHz, the pulse width is 243ns, the amplitude is 4.39kV, the frequency is 40kHz. The volt-ampere characteristics of GaAs avalanche samples at high temperature are measured. It is found that at high temperature, the sample exhibits a significant current-controlled negative resistance, which is different from the volt-ampere characteristic at room temperature. The electric field locking characteristic of the sample disappears at high temperature, and the sample exhibits negative resistance whether in the process of booster or in the process of lowering the voltage. The value of negative resistance decreases with the increase of temperature and reaches 2.4 M 惟 at 70 鈩，

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