【作者】 黄颋挺；

【导师】 王少荣；

【作者基本信息】 华中科技大学 ， 电力系统及其自动化， 2007， 硕士

【摘要】 随着现代电气实验室、软件无线电、通信、图像采集等领域中数字处理技术的发展,对信号采集的速度及精度提出了越来越高的要求。但限于ADC速度的限制,一般只能采用低速ADC,通过特定方法,对高速信号进行采样。例如等价采样技术,简单地说就是在周期信号的一个或多个周期中只进行一次采样,利用周期信号的重复性,每次采样比上次偏移一个相位,从而采集整个波形。但该方法只适用于周期信号的采集。我们要研究的是可以采集各种信号波形的实时超高速采集方法。时间交替采样系统利用M片采样速率为fs/M的ADC进行前端并行逐次采样,后端拼接的技术使整个采集系统的等效采样率达到fs。但这种结构会引入通道失配误差,不加以校正会严重影响整个ADC系统的性能,且校正的实现有一定难度。在超高速数据采集系统中,还是应尽量使用单片ADC构成数据采集系统。本文从结构上可分为五部分:先对A/D芯片与数据采集板的现状和发展趋势进行全面分析;再研究非均匀采样数据的校正算法,并针对两片A/D交替采样的情况,提出了误差测量与校正算法;然后提出用两片A/D芯片并行分时采样,采样速率达400MSPS、分辨率为13bit的数据采集系统设计方案,另外还提出了用单片超高速A/D芯片实现采样速率达800MSPS、分辨率为8bit的数据采集系统设计方案;最后介绍超高速数据采集系统装配中的问题与心得。更多还原

【Abstract】 With the development of modern electrical laboratory, communication and image acquisition, higher and higher acquisition speed and precision are recommended. But the speed of ADC is constraining the development of acquisition system. Usually we use some method with low speed ADC to satisfy the high speed requiment. For example, the equivelent sampling technologh sampled only once in one or several cycle times, and use the repeatability of cycle signal to reform the whole wave. But that method is only suitable for cycle signal. My aim is to find a high speed acquisiton method which is suitable for all kinds of signals.The time interleaved ADC system works as: M parallel ADCs work with a sampling frequency fs/M and the system output are multiplexed together. This gives an overall sampling frequency fs. The drawback with this structure is the channel mismatch errors will occur in the system. These mismatch errors will degrade the system performance if they are uncorrected, and the correction is a complex work. It’s recommended to use one piece of ADC in ultra high-speed data acquisition system.The work of this paper is introduced as follow: First, analysing the actuality and future of A/D chip and data acquisition system; Second, researching the revise arithmetic of non-uniform data acquisition based on two channel parallel A/D; Third, introducing a system using two pieces of A/D sampling time-sharing, then offering another one using one piece of ultra high-speed A/D; Final, explaining the key points of setup of ultra high-speed data acquisition system.更多还原