文中介绍了一种抑制直接数字频率合成（ＤＤＳ）时由相位截断误差引起的杂散分量的方法——相位抖动法。这种方法通过给相位累加器加入抖动，来打乱相位截断误差序列的周期性，将其变为随机序列，这样就把原来由于误差序列周期性引起的有规律的杂散分量变为幅度较低的随机相位噪声，从而降低了输出的杂散信号电平与有用信号的电平之比，达到改善输出频谱特性的目的。本文对该方法做了深入的分析，给出了分析结果，最后用仿真手段验证理论分析结果。 In this paper, a method to suppress the spurious components caused by phase truncation error in direct digital frequency synthesis (DDS) is introduced. This method disrupts the periodicity of the phase truncation error sequence by adding jitter to the phase accumulator and turns it into a random sequence, thus turning the regular spurious components originally caused by the periodicity of the error sequence into amplitude-less Low random phase noise, thereby reducing the output spurious signal level and the ratio of the useful signal level, to achieve the purpose of improving the output spectral characteristics. This paper does an in-depth analysis of the method, gives the results of the analysis, and finally verifies the theoretical analysis by simulation.