Design And Experimental Study Of A Nanosecend Pulse-Compressing Device

High-power subnanosecend electromagnetic pulse has various unusual military and civil application potentials for its characteristics of high power,wide spectrum and short pulse and is focused widely both home and abroad. The creation of the high power sub-ns pulse is usually produced the high voltage pulse of ns class (several nanoseconds or several ten nanoseconds) by the high voltage pulse source first, and then using the subnanosecond switch sharps the front edge and cuts the back edge. This kind of method energy efficiency is very low.A kind of valid method,making use of a short forming-line with low resistance and a sub-ns quick switch, compressing the ns-pulse produced by the pulse source, can enhance the output power and energy efficiency. Pulse-compression technique based on the single tube forming-line pulse source have been already reported in the world, but the technique based on the Blumlein (double tube forming-line) pulse source, haven't yet seen a public research thesis. This paper chooses the latter to carry on a research, having very important research meaning with the applied value.The thesis analyzed the basic principle of the Blumlein pulse source charging the short forming-line with low resistance to carry out the pulse-compressing. And the calculation formulas of the output voltage,the power gain and the energy efficiency under ideal circumstance are given. The circuit model is set up by circuit simulation software PSpice and the theoretical analysis is verified by simulation. The main pulse waveform and its infection to output pulse are simulated at the same time. The results indicate that the charging time of low-impedance compressing lines becomes longer and the peaking value of the charging voltage becomes lower. The charging voltage of the compressing lines can be enhanced effectively by means of adding a length of transmission line between the preceding stage source and the compressing line to elongate the arriving time of the reflection pulse.According to the gas breakdown theory, the thesis analyses and studies the influence of the high pressure gas sub-ns switch working characteristic to the result of the pulse-compressing. The result express:The switch spark inductance is the main influence factor to the output pulse front and back edges,pulse-width,output voltage and power gain. The research consider:minishing switch gap and carrying out multi-channel conducting is the valid technique path that lets up the switch inductance, this is also the key of the switch design. Aiming at the typical Blumlein pulse source——compact Tesla high voltage pulse source(CKP-1000), the pulse compression device and measuring system are designed, and the pulse compression experiment system is built up. The pulse-compressing experiment is carried out. The 4.5 ns input pulse is successfully compressed into the pulse with front edge of 940 ps,half high width about 1 ns, the output power gain is 2.2 or so. The experiment data is basically agreed with theoretical analysis.