| 摘要: |
| 在理想条件下分析了直接数字频率合成（DDFS）输出信号的主频谱，在此基础上，引入了延时叠加法来减少其杂散分量，本文也讨论了DDFS线路中器件本身的非理想特性引起的量化噪声及减小量化噪声的方法，采用上述这些方法后，DDFS输出信号的频谱中的杂散和噪声得到了较大的改善，如要进一步抑制DDFS的杂散和噪声，则应考虑应用DDFS＋PLL方案。 |
| 关键词: 直接数字频率合成 杂散抑制方法 相位累加器 量化噪声 DDS锁相环 DDFS |
| DOI：10.3969/j.issn.1001-893X. |
| Revised:April 28, 2002 |
| 基金项目: |
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| Research on Spurious Reduction of Direct Digital Frequency Synthesis |
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| Abstract: |
| Under ideal condition the main output spectrum of DDFS is analyzed,and on this basis a method used to reduce the spurious of DDFS based on delay overlaping is introduced. Quantization noise due to inperfect speciality of DDFS and reduction method of quantization noise is also discussed. After adopting these reduction methods mentioned above the spurious and noise of output of DDFS is improved observably. If further reduction of spurious and noise of DDFS is required, the scheme of DDFS + PLL should be adopted. |
| Key words: DDFS,Phase accumulator,Spurious suppession,Quantization noise,DDS PLL |
