多通道高速相参同步数据采集与存储系统设计

在某些电子测量测试应用场合里,要求对模拟信号进行相参数据采集,采集系统使用的采样时钟、数字下变频时钟和触发信号均由某个高稳时钟源通过分频和倍频得到,这样可以保证采集到的信号严格保持原始信号的相参性.目前广泛应用的美国国家仪器（National Instrument,NI）高速数字采集系统没有采样时钟和数字下变频时钟采用同一个外时钟源的模块,需要在现有模块的基础上进行二次开发.针对这个需求,采用目前市场上常见的NI模块,构建了采用外时钟的多通道高速相参同步数据采集与存储系统.对系统时钟变换、数字正交下变频和高速流盘等系统设计的几个关键技术,进行了详细分析并给出设计方案.

Design of high-speed multi-channel coherent synchronized data acquisition and storage system

In some electronic measurement and test applications, analog signals are needed to be sampled coherently. The sampling clock,down-converting clock and trig signals are all generated from one high accurate clock source via divider and muhiplier, thus the coherency of the original signal can be strictly reserved. The widely used N1 （National Instrument） high-speed data acquisition and storage system has no such module that its sampled clock and down- converting clock are transformed from the same external clock source, thus secondary development based on existing modules is needed. According to this particular requirement, we use COTS （commercial off-the-shelf） NI modules to build a multi channel coherent synchronized data acquisition and storage system using external clock. Several key technologies, such as system clock transformation, digital quadrature down conversion and high speed storage, et al. , are analyzed in detail and their design scheme are proposed.