摘要
宽带中频数字下变频在雷达系统中有着重要的应用,文中设计了一种基于FPGA的低通滤波法,以实现数字下变频(DDC),同时详细分析了NCO输出杂散的来源和关系,并提出了一种针对FPGA的改进FIR滤波器实现方法。最后给出了一种采用PMC板型,实现105Msps采样速率、14bit采样精度的中频数据采集方案,并给出了系统的测试结果。
Wide band and Intermediate frequency of DDC is significant in Radar system.The dissertation focuses on the low pass filter which is base on FPGA and explains the causes of output spurious frequency of NCO as well as the relationship among them.Besides,it describes a kind of realization of improved FIR filter aiming at FPGA.Finally,it presents a scheme of median frequency sampling,which reaches the sampling rate of 105M and sampling precision of 14 bits.
出处
《弹箭与制导学报》
CSCD
北大核心
2005年第S3期250-253,共4页
Journal of Projectiles,Rockets,Missiles and Guidance
关键词
中频采样
数字下变频
正交相位检波
direct sampling of IF signal
DDC
quadrature coherent detection
