High-speed High-precision Data Acquisition System Is Developed

In radar signal and information processing system, data acquisition system is indispensable as a very important unit. The development of modern radar digital signal processing and software radio technique put forward the more and more high request to the speed and precision of data acquisition system . In modern radar system, wide or ultra wide band radar signal is used more widely. Accordingly, by using digital signal processing, we need high-speed data acquisition system to get information. In traditional radar receiver, the consistency of phase-and-amplitude is imperfect, which limit the performance achievable from signal processors. To overcome this problem, we think to digitized the signal at medium frequency, even RF, and then demodulate it in digital domain. In the same, only the high-speed data acquisition system can satisfy the requirement.The development of high-speed and highprecision data acquisition system is dependent on the development of A/D chips. For the present, there have been some reports about the development of high speed data acquisition systems, the sampling frequency of which is already over 1 GSPS. However, the resolution of its is generally not over 8 bits. The lower resolution limits the quantity of the whole signal processing system. Along with the advancement of the performance of the products of A/D chips, increasing the resolution at the same time of keeping the high sample frequency is a important lesson that is urgent to resolve. Research of the dissertation is based on the high-speed data acquisition system. According to the defferent position in receiver of ADC, this dissertation discusses several types of the digital receivers, explains that it is currently a development trend of digital receivers to make ADC closed to the antenna as possible, and indicates the importance of high speed and high accuracy data acquisition system in digital receiver. About the data acquisition system's performance, we get the method of evaluating the system by theory of quantification. Combining with theoretical analysis, design and develop a suit of 200MSPS, 10-bit high-speed data acquisition system, and some techniques on design and implementation of high speed data acquisition system is discussed. The test result indicates that the sampling frequency of the data acquisition system reaches 200MHz and the ENOB of it reaches 8.19 bits.The major contents of this dissertation as below:Discuss the application and request of data acquisition system in modern radar signal processing and software radio technique, so clarified the task and meaning of this lesson.Discuss the basic theory of data acquisition system and the method that how to get the effective bits of data acquisition system.Introduce in detail the design and implementation of the high-speed and highprecision data acquisition system and the design and implementation of the specific interface conversion circuit board.System debug and performance test of the high-speed data acquisition system.Acquire and process the IF LMF signal.