一种高精度、频率连续可调的信号源的设计

Development of a novel signal generator with high precision and adjustable frequency

分析DDS技术的工作原理基础上,采用了DDS技术,以微控制器MSP430F135为主控电路,AD9833芯片为核心,开发了一种频率范围设定宽、频率连续可调、响应速度快的信号源发生器,并对该信号发生器的系统结构和软硬件进行了详细的设计。针对传统计算频率控制字存在的计算量大、频率设定效率低、占用存储空间大或设定频率有误差累积效应等缺点,研制了一种新的计算频率控制的算法,该方法不需计算大量数据、不需大量存储空间而且可显著减低误差的累积效应,可有效应用于信号源的设计中。

Basing on analyzing the principle of direct digital synthesis（DDS）,a kind of signal generator of wide frequency range set,adjustable frequency and fast response is developed with MSP 430F135 microcontroller as main control circuit,AD9833 chip as core.The system structure and software and hardware of this signal generator are designed detailedly.To address the shortcoming of large computation,low efficiency of frequency setting,more storage space occupied or significant cumulative errors of frequency setting when calculating frequency control word with traditional methods,a novel calculation way for frequency control word is researched in this paper.This new method does not need large computation and more space and simultaneously it can decrease the error greatly and it can be applied effectively in designing signal generator.