Ultra-wideband Bipolar High Voltage Pulse

The Ground Penetrating Radar (GPR) is a new type and effective detecting equipment for object which is under shallow ground. It is widely used for detecting of hydrological and engineering geology, and is playing a more and more important role. The antenna system of GPR is a key part of GPR. The short pulse generator is an important basic circuit of GPR.In this thesis, the current research status and performances of the short pulse generator are summarized; the physical principle of avalanche transistor is analyzed; and avalanche transistor is chosen based on the principle. A high-voltage ultra wide band (UWB) bipolar pulse generator has been developed, which can generate up to hundreds volts or even more in magnitude, and the pulse front-edge and trailing-edge in the nanosecond or even lower magnitude.The pulse generator has been developed mainly by using avalanche transistors. This circuit mainly includes two parts: the UWB unipolar pulse producing part and the bipolar pulse shaping part. A narrow pulse with high voltage and short leading part is generated through the combination of avalanche transistors and the MARX Bank circuit. The bipolar pulse with good waveform is obtained based on transmission line theory and the lumped parameter equivalent circuit. At the same time, bipolar pulse circuit is simulated in advance and experimented in emulation by using PSPICE software.The high-voltage UWB pulse generation technology has extensive application prospect. Our research results can be used for ultra-wideband radar, cell electro-manipulation, distance measuring in civil fields and conceal targets detection in military fields, and so on.