数字倍频器用于周期信号频谱分析的补偿和误差分析

在周期信号数字频谱分析中，数字倍频器可被用作采样频率发生器（ＳＦＧ）为ＡＤＣ提供采样脉冲，但原有的数字倍频方法使得ＳＦＧ的输出脉冲存在较大的位置累积误差。本文针对原有数字倍频方法的缺点而提出了新的补偿方法，并用非均匀采样信号理论和数字频谱分析方法导出了用原有方法和新的方法实现的ＳＦＧ所对应的采样信号序列的信噪比表达式，证明了新方法优于原有方法，同时也得出了对ＳＦＧ的设计有指导意义的结论。最后，计算机仿真验证了本文结论。

Compensation and Error Analysis of Digital Frequency Multiplier for Spectrum Analysis of Periodic Signals

In the digital spectrum analysis of periodic signals, a digital frequency multiplier can be used as a signal frequency generator(SFG) to offer the sampling pulses for the ADC, but the output pulses of the SFG based on earlier digital methods of frequency multiplication have a accumulated position error which is large in some case. This paper presents a new compensation method to eliminate this drawback, and derives the SNR expressions of the sampled signals determined by the old and the new SFGs respectively by using nonuniformly sampled signal theory and digital spectrum analysis method. Based on those derived SNR expressions, it proves that the new method has the advantage over the old ones, and gets some worthy results which are helpful to the design of SFG.