基于双中频并行采样的数字I/Q信号获取  

Generate the Digital I/Q Components Based on the Parallel Sampling of the Double-IF

作　　者：王国庆[1] 周翔凤[2] 魏玺章[3] 卢焕章[3] 

机构地区：[1]海军航空工程学院电子信息工程系,山东烟台264001 [2]山东工商学院计算机基础教学部,山东烟台264005 [3]国防科技大学电子科学与工程学院空间电子信息技术研究所,湖南长沙410073

出　　处：《信号处理》2011年第1期6-13,共8页Journal of Signal Processing

摘　　要：针对大时宽带宽积信号模拟正交解调幅相误差大的问题,提出了一种基于双中频并行采样的数字I/Q信号获取新方法,该方法首先对回波的两路不同中频信号在特定时刻采样,而后进行符号变换来得到高精度数字I/Q信号。设计了具有固定的相位正交性误差自校正功能的双中频数字正交解调结构,该结构简单且易于工程实现,与模拟正交解调结构比较,镜频抑制比改善15dB左右。仿真实验验证了该方法的正确性。Aiming at the poor I/Q mismatch of the analog quadrature demodulation topology under the condition of the large time-bandwidth product signals,a new method of generating the high precision digital I/Q components based on the parallel sampling of the Double-IF which by the given sampling of the different IF of the echo signal and the subsequent sign changer is proposed.The Double -IF quadrature demodulation topologies which fixed phase imbalance can be autocorrected are designed.The topologies are easy to be implemented and with the improvement of about 15dB compared to the traditional analog quadrature demodulation topology in the image rejection ratio（IRR）.The simulation experiment gives the correctness and validation of the method.

关 键 词：大时宽带宽积信号 双中频 并行采样 正交解调 镜频抑制比 

分 类 号：TN95[电子电信—信号与信息处理]