Li Jiangtao, Zhao Zheng, Li Longjie, He Jiaxin, Li Chenjie, Wang Yifeng, Su Can
School of Electrical Engineering, Xi'an Jiaotong University, Xi'an 710049, China.
Rev Sci Instrum. 2017 Sep;88(9):093514. doi: 10.1063/1.5003390.
A transmission line transformer has potential advantages for nanosecond pulse generation including excellent frequency response and no leakage inductance. The wave propagation process in a secondary mode line is indispensable due to an obvious inside transient electromagnetic transition in this scenario. The equivalent model of the transmission line transformer is crucial for predicting the output waveform and evaluating the effects of magnetic cores on output performance. However, traditional lumped parameter models are not sufficient for nanosecond pulse generation due to the natural neglect of wave propagations in secondary mode lines based on a lumped parameter assumption. In this paper, a distributed parameter model of transmission line transformer was established to investigate wave propagation in the secondary mode line and its influential factors through theoretical analysis and experimental verification. The wave propagation discontinuity in the secondary mode line induced by magnetic cores is emphasized. Characteristics of the magnetic core under a nanosecond pulse were obtained by experiments. Distribution and formation of the secondary mode current were determined for revealing essential wave propagation processes in secondary mode lines. The output waveform and efficiency were found to be affected dramatically by wave propagation discontinuity in secondary mode lines induced by magnetic cores. The proposed distributed parameter model was proved more suitable for nanosecond pulse generation in aspects of secondary mode current, output efficiency, and output waveform. In depth, comprehension of underlying mechanisms and a broader view of the working principle of the transmission line transformer for nanosecond pulse generation can be obtained through this research.
传输线变压器在纳秒脉冲产生方面具有潜在优势，包括出色的频率响应和无漏感。由于这种情况下明显的内部瞬态电磁转换，二次模线中的波传播过程是不可或缺的。传输线变压器的等效模型对于预测输出波形和评估磁芯对输出性能的影响至关重要。然而，传统的集总参数模型对于纳秒脉冲产生并不适用，因为基于集总参数假设，它自然忽略了二次模线中的波传播。本文建立了传输线变压器的分布参数模型，通过理论分析和实验验证来研究二次模线中的波传播及其影响因素。强调了磁芯引起的二次模线中的波传播不连续性。通过实验获得了纳秒脉冲下磁芯的特性。确定了二次模电流的分布和形成，以揭示二次模线中的基本波传播过程。发现磁芯引起的二次模线中的波传播不连续性对输出波形和效率有显著影响。所提出的分布参数模型在二次模电流、输出效率和输出波形方面被证明更适合纳秒脉冲产生。通过这项研究，可以深入理解其潜在机制，并更全面地了解传输线变压器用于纳秒脉冲产生的工作原理。
