Design Of Time Interval Measurement System Based On Phase Processing

As one of the basic physical quantity, the time measurement is usually defined time and time interval. As a fundamental study in the field of time and frequency measurement and control, the application for high precision time interval measurement principles and methods are very widely involved, whether in engineering fields, including communication, laser ranging, satellite navigation and positioning, or the basic scientific research areas, such as chip design, atomic physics, astronomical observation. The research and realization for time interval measurement method usually come from two aspects: the analog and digital method. The former has high measurement accuracy, but the structures of measurement instruments are relatively complex, especially in the high frequency signal processing referred to high frequency electronic circuit design. The latter will be caused quantization error in the measurement process, restricting the precision measurement in accuracy and resolution requirements. Therefore, it is becoming a topical issue in the field of time-frequency measurement and control that simplify the measuring circuit but not affect the resolution and measuring precision for time interval measurement system.According to the related theories and methods in recently years in the areas of time and frequency measurement and control, combined with the conventional measurement methods, a novelty time interval measurement system with good performance is put forward and designed that can simplify the measuring instrument but still has high precision. It is based on phase processing theory. Through the pulse cluster from fuzzy area sampled by high-speed ADC, we can obtain the relations between the phase difference and the sampling voltage value, and realize the time interval measurement.Through research the theory of frequency measurement and control field in this article, and analyze the advantages and disadvantages in conventional time measurement methods, the system whole design is formulated. Through to test the system function and performance and analysis of test data processing in detail, the design steps of the time interval measurement scheme is obtained. As the key early measured signal processing chip, digital circuit part for the measuring equipment is integrated in FPGA, simplifying the complex signal processing circuit module, improving the system stability, and at the same time, enhancing the system reliability. Finally, the resolution achieved is less than 100 ps by the system. Despite the quota is not very well compared to the commercial instrument, it has the advantage to simplify the hardware structure to the regular instruments. Through introducing the theory of phase processing, the voltage and time measurement is connected indirectly. It is a new measurement concept and it will provide a fully novelty measurement method and thought for the measurement of other physical quantities in measurement field.