频域校准相位抵消法的低中频接收机设计  

Low-IF receiver using frequency adjustation and phase cancellation

作　　者：苏郢[1] 杨子杰[1] 

机构地区：[1]武汉大学电子信息学院,湖北武汉430079

出　　处：《华中科技大学学报（自然科学版）》2009年第3期39-42,共4页Journal of Huazhong University of Science and Technology(Natural Science Edition)

基　　金：国家高技术研究发展计划资助项目(2001AA631050)

摘　　要：分析了射频接收机中镜像干扰的产生以及一次混频超外差接收机、中频直接采样接收机、两次混频超外差接收机抑制镜像干扰的方法.提出了基于频域校准相位抵消法的低中频接收机方案,同时分析其性能以及I,Q两路的相位、幅度误差带来的影响.基于线性调频中断连续波(FMICW)雷达对这种方案进行了仿真,将其速度、距离谱与未经过镜像抑制处理时的情况进行了比较,结果表明该方案对镜像抑制效果有所提升,基于数字信号处理的校准提高了镜像抑制比.The reason why hermitian image generates in the radio frequency receiver, and the way how to reject hermitian images in some receives, such as one-time mixing superheterodyne receivers, direct sampling ones with intermediate frequency and twice mixing superheterodyne ones, were discussed. The plan of low-IF （low-intermediate frequency） receiver based on frequency adjustation and phase cancellation method was proposed. The performance of the plan and the effects caused by phase and amplitude error in I and Q path were given. The method was simulated by frequency modulated inter- rupted continuous wave （FMICW） radar to get the comparisons between speed and distance spectrum processed with hermitian image rejection and original spectrum of speed and distance. The result showed that hermitian image rejection had been improved tremendously. Since the signal was adjusted in frequency domain, this adjustment grounded on digital signal processing greatly increaseed hermitian image rejection ratio, with its superiority of precision than other analogue methods.

关 键 词：接收机 相位抵消 镜像抑制 低中频 相位误差 幅度误差 

分 类 号：TN958[电子电信—信号与信息处理]