级间有耦合传输线的脉冲变压器除第一级传输线外所有传输线均绕制在同一磁芯上。利用电路等效法对该变压器进行了理论分析,结果表明：相比采用其他绕线结构的传输线变压器,该传输线变压器的顶降更低,而且仅需要一块磁芯。根据该设计方法,研制了一台四级传输线脉冲变压器,变压器的输入阻抗为4.2 Ω,输出阻抗为67.7 Ω。利用该变压器对脉冲形成网络(PFN)形成的脉冲进行电压变换,变压器匹配负载上输出电压脉冲脉宽为120 ns,前沿为20 ns。该脉冲幅值是PFN对4.2 Ω负载直接放电形成脉冲幅值的4倍,且两者波形基本一致。

A transmission line transformer(TLT) with mutually coupled windings is described in this paper. All transmission lines of the transformer except the first stage are wound on a common ferrite core. A equivalent circuit method is introduced to analyze this model and an analytic expression of step response is derived. It is shown that TLT with the above-mentioned structure has a significantly slower drop rate than those with conventional structures. A four-stage TLT with this structure whose input and output impedance are 4.2 Ω and 67.7 Ω respectively was developed. A pulsed power source based on the TLT was developed, which generated voltage pulse with pulse width of 120 ns, and rise time of 20 ns. Amplitude of this pulse is four times of that generated by pulse forming network discharging on a load of 4.2 Ω directly, and these two voltage waveforms have almost the same temporal shape.