探地雷达高功率高稳定度脉冲源设计

 对于探地雷达，脉冲源的功率和稳定度直接影响其作用距离和探测精度，对目标成像时进行相干积累有着重要意义。采用雪崩三极管设计的全固态脉冲源具有很高的稳定度指标，但输出功率较低，使用Marx电路可以提高其输出峰值电压幅度。梳状PCB(印刷电路板)电路是一种结构紧凑具有自相似性的电路形式，有利于进一步提高脉冲源的稳定度指标，也有利于脉冲源的小型化设计。根据某探地雷达要求，采用梳状PCB电路形式，实现了12级Marx电路的脉冲源，采用欠电荷法对脉冲波形进行了优化设计，其输出峰值电压大于400 V(50 Ω负载)，脉冲宽度为600 ps，重复频率大于25 kHz；并且具有良好的时基稳定度和波形稳定度，脉冲宽带抖动小于1%，峰值抖动小于1%。

High-power and high-stability pulser for ground penetrating radar

The action distance and detection precision of ground penetrating radar(GPR) is directly restricted by the power and stability of its pulser.The stability of the pulser based on avalanche dynatron is good,and it is propitious to improve the detection precision of GPR,but its peak-voltage is lower.In order to increase the output peak voltage of pulser,Marx circuit is used,and its structure is designed for strict comb PCB(printed circuit board) layout.Finally,for a practical GPR,a pulser is designed with 12-stage Marx circuit.The test results are that its peak voltage is higher than 400 V,the pulse width is 600 ps,the repetition frequency is higher than 25 kHz,both the pulse width jitter and the peak voltage jitter are less than 1%.