基于数字补偿的快速频率合成方法的研究

A Fast frequency synthesizer technique based on digital Pre-compensatation

基于I/Q调制的快速频率合成方法比目前采用的频率合成方法更易调试,而且使用灵活。其思路是将信号先通过单边带调制,将较低频率调制到需要的频率范围;然后采用对基带信号的数字预补偿方法来抑制镜像频率和载波泄漏,从而达到应用的目的。文章中还给出一种基于输出信号包络信息的补偿系数调整算法,其仿真结果说明该新补偿算法可以有效抑制镜像频率和载波泄漏。

A frequency synthesizer technique based on L/Q adjustment makes it easier to debug and use comparing with the ongoing method. First, a low frequency tone is up- converted to the needed frequency range by means of SSB （ single side band modulation）. Then we perform digital pre - compensation method, which can be used in the processing of base band signal to reject image frequency and protect carrier leak to meet the ap- plication purpose. Furthermore, an algorithm according to the envelope of out signals for updating the compensator coefficients is proposed. Simulation results illustrate the excellent performance of the proposed pre - compensation structure can significantly reject image frequency and protect carrier leak.