直接数字频率合成中相位截断误差分析

Analysis of Phase Truncation Errors in Direct Digital Frequency Synthesizers

直接数字频率合成具有相位噪声低、频率分辨力高和频率切换快等优点，但其合成的波形中含有大量的杂散分量，其中之一是由于相位截断引起的。本文用傅里叶级数的方法分析了合成波形的频谱特性，并对由于相位截断引起的杂散谱作了讨论。

The direct digital frequency synthesizer(DDS) has the advantages of low phase noise,high frequency resolution and fast frequency switching.However,there are a lot of spurious components in the output waveform or DDS.The phase truncation crror is one of the spurious sources.This paper analyzes the spectral characteristic of the synthesized waveform by use of the Fourier Series,and discusses the spurious spectrum of the phase truncation errors.