Optimized analysis of sharpening characteristics of a compact RF pulse source based on a gyro-magnetic nonlinear transmission line for ultrawideband electromagnetic pulse application

摘要

We constructed a compact high-power RF pulse generator based on a gyro-magnetic nonlinear transmission line (GNLTL) to produce a high-voltage pulse with a sub-nanosecond rise time and a relatively high repetition rate,which shows great potential for application in the high-power ultrawideband electromagnetic effect,etc.The influence of incident pulse parameters (rise time and voltage amplitude) and line length on the sharpening characteristics of the GNLTL were investigated experimentally to optimize the rising rate of the modulated pulse front.Based on the GNLTL equivalent circuit model consisting of an LC ladder network,the rise time,the voltage conversion coefficient and the rising rate properties of a modulated pulse were also numerically analyzed in a wider range.The results show that a ＞ 90 kV RF pulse with a rise time of 350 ps and a repetition rate of 1 kHz in burst mode is produced by the GNLTL at an axial biasing magnetic field of 22 kA m-1 and a line length of 30 cm under the condition of a 70 kV incident pulse.Applying a faster and higher incident pulse is conducive to improving the sharpening effect of the GNLTL.Furthermore,within a certain range,increasing the line length of the GNLTL not only reduces the rise time,but increases the voltage conversion coefficient and the rising rate of a modulated pulse.Furthermore,considering the energy loss of ferrite rings,there is an optimal line length to obtain the fastest rising rate of a modulated pulse front edge.