为了产生较高中心频率宽带高功率微波,对一种填充变压器油作为绝缘介质的1/4波长开关振荡器进行了研究。首先对这种开关振荡器特性阻抗分布进行了分析; 然后利用静态电场仿真结果和变压器油击穿实验数据,分析了该振荡器的耐压能力; 在此基础上,利用CST软件对其瞬态工作特性进行了仿真,考察了开关间隙击穿位置和间隙电压下降时间对产生阻尼正弦信号的峰值和频率的影响; 最后介绍了该振荡器以一种方向系数为3的短螺旋天线作为辐射天线的实验测试结果,结果表明,该开关振荡器充电电压上升时间为15 ns时,耐压达到-322 kV,产生宽带高功率微波中心频率约360 MHz,3 dB带宽约22%,辐射因子170 kV。

To generate wideband high power microwave with relatively high central frequency, a quarter wave switched oscillator filled with transformer oil as insulating medium is investigated in this paper. Firstly, the structure of this oscillator is introduced. Secondly its characteristic impedance is calculated. Thirdly, the voltage capability is estimated by the simulation results of static electric field distribution and experimental data of the breakdown electric field of the transformer oil. And then the transient performance of the oscillator is simulated by utilizing CST software. The influence of the breakdown position and down-time of the voltage between the switch gap on the peak voltage and central frequency is also investigated. Finally, the experimental result of the oscillator connected to a short helical antenna with a directivity of 3 is introduced. It is shown that the breakdown voltage of the oscillator reaches -322 kV when the rise time of the charging voltage is about 15 ns. The center frequency of the radiated electric field is about 360 MHz with a 3 dB bandwidth of about 22%, while the radiation factor is about 170 kV.