在DDS波形发生器中相位截尾噪声的分析和抑制

直接数字频率合成技术（DDS）是近年来发展迅速的一种新的频率合成技术。全数字化的结构赋予了它很多的优点：频率转换时间短，频率分辨率很高，输出相位连续，容易集成和易编程控制等，当然也就引进了数字化结构的缺点－－输出杂散在。本文对DDS波形发生器中由于相位截尾所产生的杂散进行分析，并提出抑制相位截尾噪声的方法，给出了实现方法和实验结果。

The Analysis and Restraint of the Phase-truncation Noise in the DDS

Direct digital synthesizer (DDS) is a new developed frequency-synthesizer technology. The all-digital structure of the technology gives itself many advantages, such as the very short frequency-transition time, the very high frequency resolution, the successive phase output under the frequency transition and its easier programmed character. At the same time the all-digital structure of the DDS brings its disadvantages: the high output noise. This paper analyzes the noise produced by the phase-truncation and put up a means by which we can restrain its high output noise.