基于多路DAC伪插值的任意波形合成技术研究

Research of arbitrary waveform generation based on pseudo interleaving of multiple DACs

针对任意波形发生器的设计中数模转换器(DAC)转换速度的瓶颈问题,提出了一种基于多路DAC进行伪插值的任意波形合成方法,从理论上证明其可行性,并对其实现过程中的误差来源进行了探讨,给出了相应的补偿思路。着重分析了DAC零阶保持特性和伪插值时钟误差对输出信号频谱的影响,推导了关于频域特征和信噪比的重要结论。并通过计算机仿真和500 MSPS任意波形发生器项目对结论进行了验证。这些结论可用于任意波形发生器设计中的杂散评估和方案选择,同时也可为指标分配提供理论依据。

Digital to analog converter （DAC） is a key part of arbitrary waveform generator. Aiming at the bottleneck of DAC sampling rate, a method of arbitrary waveform generation based on pseudo interleaving of multiple DACs is put forward and proved in this paper. The error of pseudo interleaving is discussed and some compensa- tion methods are given. The spectrum of pseudo interleaving under zero-order hold and clock error are studied, then several important conclusions are drawn, which can provide theoretical supports for spurious performance evaluation and parameter selection in arbitrary waveform generator design.