Development Of Differential And Integral Divider For Pulse High-voltage

With the rapid development of science and technology,our living environment is constantly changing and the electromagnetic hazards are everywhere.Electromagnetic pulse is a transient phenomenon.In the time domain,it has very short rise time and narrow pulse width.In the frequency domain,the frequency band is wide.Therefore the measurement is difficult in researching pulse electromagnetic field in the high voltage pulse generation andset up the experimental system.A differential and integral divider for high-voltage pulse was designed in this paper.The response time is about Ins and the withstand voltage can reach more than 20kV.The main works of research are as follows:1)The electromagnetic pulse was analyzed in time domain and frequency domain.The influence of parameters of differential and integral divider was analyzed theoretically.The realization method of differential and integral divider was presented.2)Coaxial type differentiator was analyzed by CST simulation method to find influence of the differential probe shape,size and position on the differential signal and transmission signal.Differential outer conductor and the inner conductor were designed to ensure characteristic impedance matching,and the medium was added not only can improve the pressure resistance but also increase the distance between the inner and outer conductors.Design results show that the response time of differentiator is within Ins,the frequency response can reach more than 3GHz.3)For integral part,three ways were used.The first method is software integration.Second one is passive integrator,through Cadence simulation analysis shows that the stray inductance of integral capacitance and distribute capacitance of integral resistance have the(?)atest impact on the bandwidth.Several of low resistance in series was used as the integral resistance and core capacity as integral capacitor to reduce the two stray parameters.Design results show the frequency range of passive integrator is 3MHz-310MHz.The third way is active integrator.The feedback resistor was used to reduce the integral drift,through the selection and optimization of layout,bypass and grounding method to increase the bandwidth.’I he lower frequency limit of the active integrator that designed is 35.1kHz,and the upper limit of the frequency can reach 80MHz.4)The transformation of high-voltage cable was used to improve withstand voltage.The good performance of resistance divider was chosen to make comparison.The measure results show that the shortest rise time is active integrator;Software integration has the longest fall time and due to the divider ratio,the passive integrator fall time is shorter and have large error.Divider ratio of the software integration method is stable;Because of the limit of divider ratio,the passive integrator has the worst result in stability.The software integration method can meet the requirement of measuring nanosecond high voltage,passive integrator has large error in fall time,and passive integrator has waveform jitter.