【摘要】 DDS专用芯片的控制方式固定不变,用户难以获得所需要的调频波;同时,由于FPGA具有可重配置性,且容量大,延时短,分频方便,很容易实现各种调制功能,从DDS基本原理出发,针对FPGA的工作特点,推导出了一套新的调频信号的实现方法;由该算法所得调频信号不但可以根据调制波、载波和频偏3个控制字来控制频率和调制深度,而且分辨率相当高,可达0.093Hz;此算法经MATLAB仿真表明是行之有效的。更多还原

【Abstract】 As the control modes of DDS special chips are changeless,users are difficult to get frequency modulation wave what they need.At the same time,as FPGA has the characteristics of reconfiguration,great capacity,short delay and convenient frequency demultiplication so on,it could realize easily various modulation functions.Basing upon DDS rationale,according to FPGA work characteristic,a suit of new method about the realization of frequency modulation signal is deduced.The frequency modulation signal gotten by this arithmetic not only control the depth of frequency and modulation according to the three control word about modulation wave,carrier wave and frequency deviation but also has high distinguishing ratio which could reach 0.093Hz.The imitation result by MATLAB shows that the design is feasible.更多还原