混合式频率合成技术在提高频谱纯度与扩频速度上的应用研究

单纯的DDS技术在与PLL技术在频率合成应用中各有优缺点，采用混合式频率合成技术可以将两者结合，做到取长补短。利用DDS激励PLL混合式频率合成技术实现了一种频率纯度较高、可快速数字扩频的频率合成器，并对设计过程中的问题进行了讨论。得到了优于传统技术的测试结果和频谱图。

Applied Study of Admixture-frequency Synthesize Technique on Increaseing the Rate of Purity Degree and the Frequency Expanding of Frequency Spectrum

The pure DDS frequency synthesizes or the traditional PLL frequency synthesizes has one＇s own strong points and disadvantages,making use of the admixture frequency synthesize technique, we can combine the two synthesis techniques and live up to learn from others＇s strong points to offset one＇s weakness, making use of the frequency synthesize technique that PLL stimulated by DDS,the anthor realizes a kind of frequency synthesizer which has higer purity on frequency spectrum and able to rapid spreads spectrum. Discussion of the problems on the in the process,getting better test result and frequency spectrum.