Abstract:
The paper introduces the basic principles of direct digital synthesis(DDS) and direct quadrature up-conversion(DQUC).The realization method of a broadband Doppler frequency simulator based on DDS and DQUC Techniques is proposed,which has all advantages of DDS and offers an economic approach to frequency up-conversion.At last,the paper introduces several practical measures for direct quadrature up-converter optimization based on AD9854 and AD8346,and the experiment results are presented.