Research On The Key Technology Of High Peak Power And High Repetition Frequency Time-domain Signal Source

Time-domain ultra-wideband electromagnetics is currently one of the research hotspots in the field of electromagnetics,offering significant advantages in high-speed data transmission and precise target detection.At present,it has been widely applied in radar detection,target imaging,biomedicine,electromagnetic attacks,and other fields,demonstrating its immense application potential.Avalanche transistor Marx circuits are commonly used to generate UWB pulse signals,producing high peak voltage,high peak power,rapid rise time,and highly repeatable pulse signals.The output pulse signal waveform exhibits good stability,strong controllability,and excellent anti-interference performance.Moreover,Marx circuits have additional advantages such as compact size,lightweight,and simple structure compared to other pulse signal generation methods,providing robust support for UWB pulse signal research and applications.Furthermore,Marx circuits can be optimized by adjusting the parameters of capacitive and inductive components,enhancing the performance of the output pulse signal to better adapt to the application requirements of UWB pulse signals.This study aims to develop a high peak power,high repetition frequency UWB pulse source,with improvements to the circuit structure and cooling system,ultimately achieving a significant increase in the working lifespan of the pulse source avalanche transistor.Additionally,this study proposes an innovative design approach for the optimal circuit design solution when synthesizing the power of multiple pulse sources.The specific work content of this study includes:First,the parameters and avalanche principles of avalanche transistors were analyzed,and the theoretical formula for generating high peak pulses in avalanche transistor Marx circuits was derived.Based on this foundation,suitable Marx circuit avalanche transistor models,circuit structures for each stage,current-limiting resistors,and energy storage capacitor parameters were determined according to the required peak power,pulse repetition frequency,and time jitter indicators.By simulating the pulse generation circuit,analyzing the generated pulse spectrum,and designing the substrate thickness,dielectric constant,and strip line width parameters according to the required bandwidth and characteristic impedance based on transmission line theory,a theoretical foundation was provided for the subsequent production of circuit boards.In the synthesis of multiple pulse sources,this study delved into the optimal design method for stage selection based on the derived relationship between the single-channel pulse stage and the output pulse peak.This pioneering research offers new insights for the field of multi-channel pulse source synthesis.Regarding heat dissipation,this study first estimated the equivalent resistance of the avalanche state of avalanche transistors based on theoretical pulse formulas and actual pulse data and analyzed the thermal loss distribution of the pulse source circuit accordingly.Subsequently,a direct immersion liquid cooling technique utilizing gasliquid phase change was employed,significantly enhancing the heat dissipation efficiency of the pulse circuit.The single-channel pulse source module can operate stably for more than 10 min at 120 k Hz repetition frequency and 2.6 k V output amplitude,and the average life of transistors is improved by about 10^3 times.The final pulse amplitude after the power synthesis of the 4-way pulse source module is 7.9k V,the half-peak pulse width is700 ps,and the rising edge of the pulse is 190ps.