The Transmission Characteristics Of Transient Electromagnetic Pulse And The Research Of Avalanche Transistor MARX Signal Source

Ground penetrating radar (GPR) can measures various performanceparameters of buried or hidden targets by launching the transientelectromagnetic pulse, detecting and analysis processing the signal fromreveicing devices. The transient electromagnetic pulse (TEMP) is alsocalled chock pulse. It is widly used in many fields such as geologicalprospecting and underground engineering quality test, as it has fearures ofMulti-frequency compeonets, good ground penetract performance etc.The width of such kind of signals is usually Ns middleweight and therange can be hundreds or even thousands volt. So, there are technicalcomplexities in designing high range-narrow pulse signal generator withgood stability and repetitive frequency features. The study of this paperhas important technical value and significant engineering applicationvalue.The study contents of this paper include such things: Analysising thesignal properties of TEMP transmission process, which has importantmeaning for analysis processing echo signal; On that basis, signal generator for detecting underground targets based on avalanche effect ofavalanche transistor was studied and designed successfully. The workingprinciples should be analysed first, then the avalanche process, dynamicworking and trig mode of the transistor were discussed. Finally, variousparameters and features of output TEMP were considered, its regularityof transmission performance was mainly analysed.In this paper, simulation software Multisim was used to design,analyse and simulate the pulse signal generator, construct the equivalentmodel of the circuits.The differences of TEMP from differet classes ofcircuits are analysed, also the influences to the signal waveform bydifferent circuits’ parameters. The practical circuit was determined finally.On the basis of simulate researching, circuit compontens such asavalanche transistor would be selected priority. Using MARX circuitbased avalanche transistor, optimizing pararmeters of the circuit and thedesign of high-frequency circuit.A high range-narrow pulse signalgenerator was designed.The comparision of every index between praticalsircuit outputs and simulation results verified the correction and highstability basically. The results of the study in this paper achieved the goalbasically, constructed a solid foundation for the researching works ofecho signal received and data processing.