基于AD9959的四通道高频信号源研制

设计了一种以直接数字频率合成（DDS）芯片为核心的四通道高频信号源,每通道均可独立输出1 Hz～200MHz的高频正弦波信号,输出幅度范围为1mVpp～4Vpp,谐波失真小于等于5%,且通道之间相位均独立可调。介绍了AD9959芯片的主要功能,给出了信号处理电路的设计及PCB板的电磁兼容设计。信号源经实际测试,输出频率范围、输出幅度范围和通道间相位调节等技术指标均达到设计要求。

Research on four-channel high frequency signal generator based on AD9959

A four-channel high frequency amplitude-stable signal generator based on digital direct frequency synthesis(DDS) chip was designed.Each channel can output sine wave signal from 1 Hz~200 MHz individually,amplitude range 1 mVpp~4 Vpp,harmonic distortion≤ 5%,and the phase between two channels can be set separately.Primary function of DDS chip AD9959,the signal processing circuit and EMC design of the PCB board is introduced.Key technology indexes,including the range of frequency,amplitude and phase adjustment can meet the design requirements through practice test.