基于DDS和PLL的LFMCW雷达频率源设计与分析  

Design and analysis of LFMCW radar synthesizer based on DDS and PLL

作　　者：孙吉良 何勰 申江江 董伟洁 赵艺 Sun Jiliang;He Xie;Shen Jiangjiang;Dong Weijie;Zhao Yi(Unit 91206 of Naval Aviation University,Qingdao 266000,China)

机构地区：[1]海军航空大学91206部队,青岛266000

出　　处：《国外电子测量技术》2021年第1期106-110,共5页Foreign Electronic Measurement Technology

摘　　要：根据线性调频连续波(LFMCW)雷达差频信号特性,结合调相理论分析了扫频线性度误差和接收机频率分辨率对距离分辨率的影响,然后依据理论分析结果进行了X波段频率源设计。频率源设计采用直接数字频率合成技术+锁相环(DDS+PLL)相结合的技术,对频率源各部分电路结构及芯片参数进行了分析,获得了高分辨率、低相位噪声以及高带宽的中心频率为10GHz的信号源。对该信号进行测试和拟合得到了信号的扫频线性度误差函数,为完成更高线性度的LFMCW雷达频率源设计以达到更高的距离分辨率需求提供参考。Firstly,based on the traits of beat frequency of radar signal,analyses the effects of the linearity error and the receiver frequency resolution on the deterioration of range resolution,and the model of the linearity error is given on the basis of frequency modulation signal theory of LFMCW radar.Secondly,the above analysis are applied to the design of xband frequency source of the LFMCW radar.The x-band frequency synthesizer is designed by DDS+PLL technologies together to get 10 GHz central frequency signal with high definition,low phase noise and broad width,and structure of the circuit is analysed.Finally,the linearity error is proposed and the research of the nonlinearity has provided a guidance for the design of frequency synthesizer with high linearity to meet the requirement of range resolution.

关 键 词：LFMCW雷达 频率源 距离分辨率 DDS+PLL 

分 类 号：TN958[电子电信—信号与信息处理]