DDS与PLL频率合成数字系统设计

Design of Frequency Synthesizer Based on DDS and PLL

直接数字合成(DDS)是近年发展起来的一种新型合成技术,有频率分辨率高,转换时间短,相位噪声低等特点,与锁相合成技术(PLL)配合,可以设计出频带宽、分辨率高的频率合成器。本文介绍了一种DDS+PLL的混合结构,实现了一个高稳定度的锁相频率合成系统。

This paper discusses the realization plan of the frequency synthesisis source by means of the direct digital synthesis（DDS）AD9850 and phase--locked--loop（PLL）MB1504, recommends the matters needing attention in hardware design, and analyses the phase noise and spurious characteristics of the system, finally gives the test results of the system.