用于宽带实时数字下变频的高效二次变频电路

An Efficient Quadratic Conversion Architecture for Real-Time Wideband DDC

提出一种高效二次变频结构,分两步将中频信号搬移至基带。首先,通过一种将混频器置于滤波器之后的多相滤波宽带数字下变频结构将中频信号搬移至基带附近。然后通过传统的正交混频将信号搬移至基带,能节省滤波器资源,有效地降低采样率和数据处理速率,解决超宽带数字中频处理的难题。最后通过仿真和实验验证结构的正确性。

An efficient quadratic conversion architecture for real-time wideband DDC was presented,which could move IF signal to baseband in two steps.Firstly,IF signal was moved to the vicinity of baseband by using a digital downconverter,in which mixers were placed after polyphase filters.Then,the signal was moved to baseband through conventional orthogonal frequency mixer.The proposed architecture could save filter resource and effectively reduce sampling rate and data process cost.Simulation and test results validated the new structure.