基于VHDL的直接数字频率合成器设计与实现

Design and Realization of Direct Digital Frequency Synthesizer Based on VHDL

从直接数字频率合成器(DDS)的基本原理出发,详细讨论了相位量化字长对DDS性能的影响,并给出了相位控制字与振幅控制字长度与量化信噪比的关系。结合相位量化字长为24 b、振幅量化字长为10 b的正弦波DDS设计过程,给出了查表法实现的一个DDS设计实例。文中所附代码均通过Max+PlusⅡ编译通过,可直接应用,同时,指出了改进查表法实现的DDS性能的几个基本途径。

From the principle of DDS, the quantization word length to DDS performance influence is discussed, and the relations of quantification signal - to - noise ratio to phase word length and amplitude word length is given. A detailed DDS design example,which phase quantization word length is 24 b and amplitude quantification word length is 10 b. Finally, the essential way to improve the DDS performance is pointed out.