Through the research of direct digital synthesizer (DDS) used as a divider in phase lock loop (PLL), a frequency synthesizer with small frequency resolution ratio and high purity frequency spectrum can be realized.

• 摘要通过对直接数字合成器在锁相环路中作为分频器应用的研究，使频率合成器可以在实现超细频率分辨率的同时达到高的频谱纯度。