Key Technology Research On High Peak Power Time-domain Signal Sources With Fast Response

The time-domain signal source is a type of signal source with unique characteristics.Due to its advantages such as high peak power and narrow pulse width,it has been widely used in various fields such as biomedical,chemical industry,radar,lasers,ultra-wideband communication,and high-speed photography.In these application domains,the timedomain signal source plays an important role.For example,in the field of biomedicine,high-energy pulse signals are used for transdermal drug delivery and tumor ablation.In the chemical industry,pulsed stimulation is used to generate non-thermal plasma in the atmosphere for gas ionization and dissociation to purify gases,and so on.The high peak power and narrow pulse width of the time-domain signal source can meet the high energy requirements of these applications,thus finding wide applications in these fields.Currently,there are various methods for generating pulse generators,including pulse forming networks,Blumlein lines,magnetic pulse compressors,and time-domain signal sources based on Marx circuits.Among them,Marx circuits based on avalanche transistors have become a research hotspot in the current stage.After the avalanche transistor conducts,the Marx circuit is equivalent to a series discharge of capacitors,which can provide sufficiently high peak voltage to the load and has the advantage of fast response speed.Therefore,it can achieve fast and accurate pulse signal generation.This Thesis proposes improvements based on the traditional Marx circuit to design a high peak and fast-response time-domain signal source.In order to achieve a high peak and fast-response time-domain signal source,this Thesis first determines the trend of circuit variation through circuit simulation,obtaining the trend of increasing circuit output voltage with the increase of stages and bias voltage.It is also concluded that parallel avalanche transistors can increase the output peak value to a certain extent.Then,precise parameter calculations are conducted to determine the number of stages of the Marx circuit.The trigger circuit is designed with 39 stages,and the pulse circuit is designed with 42 stages.Through multiple calculations and experimental verifications,the resistor value is determined as 20kΩ,and three capacitors with a capacitance of 68 p F are connected in parallel.Subsequently,the schematic diagram and PCB layout are created to finalize the form of the triggering front-end circuit and the device parameters,ensuring that the output peak voltage and pulse width meet the required specifications.In addition,this Thesis also designs,simulates,and tests a Wilkinson power divider.The calculation method of the core parameters of the power divider and the process of circuit simulation are detailed.The insertion loss of the 2-way power divider is approximately-4.24 d B,and the insertion loss of the 4-way power divider is approximately-7.3 d B.In order to achieve better power synthesis,the delay adjustment and jitter testing of the pulses to be synthesized are performed.The delay between each signal is less than 20 ps,and the jitter is less than 10 ps.The final output peak voltage of the pulse signal synthesized by the 2-way power divider is 6.08 k V with a rise time of220 ps.The output peak voltage of the pulse signal synthesized by the 4-way power divider is 8.24 k V with a rise time of 258 ps.The resulting pulse signals meet the requirements of fast response and high peak power.