直接数字调频中的时序分析和研究

Timing Analysis and Research of Direct Digital Frequency Modulation

利用直接数字调频(DDFM)调制器可以产生高精度的调频信号,但调制信号的抽样频率fs和DDS的参考时钟源频率fclk的匹配关系不同时所输出的调频波就会有很大的不同,从DDFM的原理出发,分析了fs和fclk的不同关系对输出调频波的影响和实际应用中需要考虑的问题,并给出了仿真结果。

A DDFM modulator can be used for providing the modulated signal with high quality. But the performance of the modulated signal is affected by the relation between the sampling frequency of modulating signal （ fs ） and the clock frequency of DDS （ fclk ）. This paper based on the theory of DDFM, analyses the effect to the modulated signal when f, and fclk are in different relationship and some problems to be considered in practice,and gives the emulational result also.