Research On Key Technology Of Systhesizing High-Speed Pulse Waveform

High-speed pulse has been widely used in modern communication systems, electronic countermeasures (ECM) systems, RF testing, digital integrated circuit testing and other fields; the high-speed pulse technique has also become a research focus in modern electronic technique field with the synthetic method and technique of the ultra-narrow pulse, fast edge pulse, precisely controlled pulse, programmable pulse with complicated waveform as the core of research. The waveform synthesis technique is mainly used to solve the generation and control of frequency information, power information and timing information of the high-speed pulse timing-domain waveform. Based on the feature analysis of the rectangular pulse together with a number of research projects of pulse generator carried out in the period of Ph.D. education, this thesis stresses the development and project fulfillment of pulse pattern generator and carries out intensive study on the following issues with the study on synthetic technique of frequency information, synthetic technique of power information and transmission characteristics of the high-speed pulse as the main part:(1) Analysis and synthesis of pulse waveform characteristics: the characteristics of time domain waveform of the pulse are analyzed, which are divided into frequency information relevance and power information relevance according to its information relevance; the correlation between the pulse width features and the signal bandwidth as well as that between the edge features and the signal bandwidth is emphasized; the synthetic scheme of waveform characteristics based on the information synthesis is put forward.(2) Synthetic technique of the frequency characteristics of pulse waveform: the study on the synthetic technique and execution scheme of frequency information-related waveform characteristics, such as the pulse period, width, interval, group characteristics and sequence properties based on the digital synthetic method is carried out; the study on the timing technique with high resolution in a wide range and the pulse width control technique with high resolution and high precision is carried out; the problem about the high resolution and high precision of the pulse width and the signal delay concerning the digital synthetic method are solved.1) Frequency generation technique of digital clock: the DDS frequency synthetic method and phase-locked loop frequency synthetic method are analyzed; the study on the influences, causes and solutions of the clock jitters is carried out; the clock frequency synthetic scheme with high resolution in a wide range by combination with DDS and phase-locked loop is designed; the clock frequency synthesis of 800MHz is successfully achieved in XXXX Pulse/Data generator project.2) Synthetic method of waveform characteristics: based on the digital synthetic technique, the waveform interception, addition of waveforms and sequence data storage are put forward for various applicable waveforms, such as the single pulse, group pulse and long sequence pulse to synthesize the relevant characteristics of frequency information; the specific execution scheme is designed; the actual application in project is provided. The pulse waveform within 1Hz~400MHz is successfully achieved in some projects.3) Pulse width with high precision in a wide range and delay control technique: the study on the timing technique with high precision in a wide range by combination of programmable count delay and multi-tap programmable transmission delay is carried out; the precision and scope of delay concerning the digital pulse is solved; the synthetic method of pulse width characteristics on basis of the relative delay and edge synthesis principle is put forward; the pulse control scheme is designed by the delay timing technique; the pulse width synthesis with a resolution of 10ps in the range of 1.25ns~1s is successfully achieved in XXXX pulse pattern generator project, which perfectly solves the delay and high resolution of pulse in the digital waveform synthesis.(3) Fast edge pulse technique: two methods of fast edge pulse generation based on special semi-conductor and non-linear transmission line are analyzed; the improved step recovery diode fast edge shaping circuit is designed with a fast edge of 80ps achieved; the project technique scheme of non-linear transmission line(NLTL) is put forward further.(4) Power characteristics synthesis & edge adjustment technique of pulse waveform: the basic principles of linear adjustment technique and its limitation in the pulse power information synthesis are analyzed and compared; a non-linear adjustment technique of pulse waveform is put forward to solve the power characteristics synthesis of high-speed pulse, the amplitude of the pulse within 1Hz~400MHz is perfectly adjusted to 0.1~3.8VPP by 10 mV resolution; two kinds of edge adjustment by combination of high-speed switching dioxide and charge & discharge of constant current source specific to the control of rise/ fall time in a wide range are put forward; the edge control in various ranges is designed and realized.(5) Pulse transmission characteristics: the particularities of pulses in transmission are analyzed; the study on the influences of non-ideal loaders on the pulse waveform characteristics is carried out; the matched conditions and implementation methods of the impedance concerning the multiple branching construction of transmission lines occurring during the development of the pulse generator are deduced on basis of the impedance matching principle.