Substantial Ultra-fast Pulse Forming Circuit

The technique of high-voltage ultra fast-speed pulse generating has the widespread application prospect. Here, high-voltage refers to the voltage in several hundreds volts even higher magnitude, ultra fast-speed refers to the pulse front-edge or trailing-edge in the nanosecond even lower magnitude. The development of various application will be blocked seriously if the two aspects of performance can't be improved. Therefore, the research has a vital significance, and gradually becomes one of hot spots which the domestic and overseas studies. Restricted by the device characteristic, for the conventional electric circuit, it is difficult to get both high-voltage and ultra fast-speed simultaneously.The work of this dissertation describes the high-voltage ultra fast-speed pulse generating circuits. Main research work, results and innovation places are as follows:1) The common high-voltage and fast-speed pulse generating circuit has been analysed, the project using avalanche transistor has been proposed to get the pulse form.Compared with other switching components, avalanche transistors are better. At present, the avalanche transistor module, in the fast development, which is based on the avalanche effect, can realize not only high-voltage output in short time, but also the megawatt (MW) power output in the magnitude, therefore the avalanche transistors are used as high-speed switching device widely.2) According to the need of the project, the circuit of manual-triggered pulse generator has been designed.According to the request of the project, the mode triggered to form avalanche pulse has been chosen from the three kinds of common avalanche modes of the avalanche transistors, and, the manually controlled trigger circuit which can prevent the shake of button has been designed, by using the numerical logic function of monostable trigger instrument 74LSxxx.3) The method of improving pulse circuit, i.e transmission line load method has been proposed.Transmission line load method is introduced based on conventional circuit, while theories of impedance matching and transmission line signal reflect are combined, the pulse which has hundreds volt voltage and nanoseconds of both front-edge and trailing-edge has been formed. The mechanism of tradition circuit is changed radically and performance of trailing-edge is improved greatly. There is no report about this until now, so far.4) Pulse circuit is simulated in advance and experimented in emulation by using emulated software.The high-voltage ultra fast-speed pulse generating circuit involves the concept of high-voltage and high-speed. Emulated software was introduced to emulate the circuit during the circuits design process. By analyzing the results of the emulation, we optimize the project, structure and the devices parameters of the circuits. So that, the cost was saved greatly, the efficiency was advanced, gist was supplied for the theoretically analyze, the performance of the circuits has been improved finally. There is no report about this until now.5) projects to improve the circuits performance.Based on the primary research, a series of measures and projects are proposed. Such as Marks Bank pulse forming network, which can get higher voltage pulse by experiment. The pulse which has kilovolts of voltage and microseconds of both front-edge and trailing-edge has been demonstrated.