DDS杂散分析及抑制方法研究

摘要

频率源是现代雷达电子系统的重要组成部分,是整个雷达的心脏.直接数字频率合成器(DDS)具有频率转换快、频率分辨率高、输出频率相对带宽较宽、产生波形灵活、相位连续及体积小等优点,缺点是工作频率有限,杂散较高.分析在理想条件下DDS输出信号的频谱,在此基础上,分析并仿真影响DDS杂散噪声的原因,提出几种有效地抑制DDS杂散的办法,对改进DDS电路的杂散有很大的促进作用.%The frequency generator is an important part of modern radar electronic system, and it is the heart of the radar. Direct digital frequency synthesizer (DDS) has the advantages of fast frequency conversion, high frequency resolution, relatively wide output frequency bandwidth, flexible waveforms, continuous phase and small size, and the disadvantage is limited frequency and higher spurious. This paper analyzes the spectrum of the DDS output signal under ideal conditions, on this basis, simulates the DDS spurious noise reasons. At last, it gives several effective suppression ways of DDS spurious to improve the DDS circuit spurious.