A Novel Multi-frequency Measurement Method for Large Trigger Delay of Digital Oscilloscopes
LIANG Zhi-guo1,YANG Ren-fu2
1.National Key Laboratory of Science and Technology on Metrology & Calibration, Changcheng Institute of Metrology and Measurement, Beijing 100095, China
2.National Key Laboratory of Science and Technology on Metrology and Calibration, Beijing Institute of Radio Metrology & Measurement, Beijing 100854, China
Abstract:Aiming at the large trigger delay of digital oscilloscope, a novel multi-frequency measurement method is presented. By using the period of sinusoidal as standard, the large trigger delay is divided into two parts, one part is just consist of many periods of sine wave, another part includes the partial period of sine wave. The partial period part can be measured through phase difference method. The integer periods part can be measured by using different frequency stimulation, of which the difference of the trigger delay value at different signal frequency has the same common period, and one can judge the minimum common period from three frequency sampling series. Then, the minimum common period can be used to calculate the number of periods. Finally, through composing of the two parts, the large trigger delay is gotten. The correctness and feasibility are proved by some experiments on digital oscilloscope, and the method can be used to the measurement and calibration of large trigger delay of digital oscilloscopes.