一种测距系统的频率源设计  

Design of a Frequency Source for a Distance Measurement System

作　　者：张冬[1] 孙军[2] 袁登荣[3] 

机构地区：[1]中国电子科技集团公司第二十八研究所 [2]南京电子技术研究所 [3]海军91329部队

出　　处：《现代雷达》2013年第12期72-75,共4页Modern Radar

摘　　要：调频连续波测距技术对扫频信号的线性度和频率切换时间提出了较高的要求。K波段测距系统中的频率源大多以三角波信号控制压控振荡器的方式产生调频连续波。压控振荡器的非线性特性使得调频连续波的线性度较低,影响测距的精度。直接数字频率合成器产生的调频信号频率分辨率高、线性度高、频率切换时间短。锁相环频率合成产生频率稳定度高、频谱纯度高的信号。该文采用直接数字频率合成和锁相环频率合成组合方式设计了一种频率源,并分析了频率源的性能参数,最后给出了测试结果。该频率源经实际使用达到了满意的效果。Higher linearity and shorter updating time is very important for frequency modulation continuous wave（FMCW） in distance measurement system. In most k-band distance measurement system, frequency modulation continuous wave is generated by voltage control oscillator（VCO） controlled by triangular wave. The precision of distance measurement is limited by nonlinearity of VCO. Di- rect digital frequency synthesizer （DDS）generates linear frequency modulated continuous wave with short frequency updating time, high resolution and linearity. Phase locked loop （PLL） synthesizer generates signal with stable and pure frequency. A frequency source was designed with combination DDS and PLL synthesizer. Performance of the frequency source was analyzed according to de- vice datasheet. Finally, test results of frequency source were given. The practical application achieved preferable effect.

关 键 词：频率源 直接数字频率合成 锁相环 调频连续波 

分 类 号：TN74[电子电信—电路与系统]