Design Of Active-head Module Of Oscilloscope Calibrator

The functions of oscilloscope calibrator are more and more important in designing, debugging and maintaining various types of analog oscilloscope and digital oscilloscope. However, the research of the oscilloscope calibration is still developing in our country. The calibrating function is relatively simple, the quality of the high-speed output signal is still low-end. Therefore, it is urgent to research an oscilloscope calibrator which can meet the increasing need of calibration.This thesis focuses on designing the active-head module for the independently developed oscilloscope calibrator. The functions including fast-edge sharpening, feedback of the amplitude of RF signal and the level of high-voltage signal and attenuation network are realized in the active-head module. Around fast-edge pulse generating technology, the radio frequency detection technology and high-voltage isolation technology, the thesis deeply research according the following problems:(1) Pulse of the front end of fast-edge sharpening generation technique: The circuit structure of the front end of the fast-edge sharpening is described, the circuit function of each level circuit is analyzed and the relationship between the levels is determined. Through the circuit design and debugging, it can meet the requirements of the input signal of the fast-edge sharpening circuit.(2) fast-edge sharpening technique: The structure and electrical characteristics of the step recovery diode are analyzed and a fast-edge sharpening scheme based on step recovery diode is proposed. Then the effects of the parameters of the step-recovery-diode are analyzed and the simulation model and circuit are designed. The design, manufacture and debugging of the circuit are carried out, and the test results are analyzed.(3) RF amplitude detection technique: the structure of the beam-lead diode is described and the compatibility in RF detection circuit in the application of beam-lead diode is analyzed. And then the RF detection circuit is designed and the simulation and debugging of the circuit are carried out, and the output signals are analyzed.(4) High-voltage level detection technique: The circuit characteristic of the high voltage circuit and the requirement of the detection circuit parameters are analyzed. Then the high-voltage level detection circuit based on high resistance isolation circuit is designed.