基于精确频率控制字的高速DDS电路设计与实现  

Design and implementation of high speed DDS circuit based on precise frequency control word FTW

作　　者：杨阳 陶建中[1,2] 万书芹[2] 邱丹 YANG Yang;TAO Jian-zhong;WAN Shu-qin;QIU Dan(School of Internet of Things Engineering,Jiangnan University,Wuxi 214122,China;No.58 Research Institute,China Electronics Technology Group Corporation,Wuxi 214035,China)

机构地区：[1]江南大学物联网工程学院,江苏无锡214122 [2]中国电子科技集团公司第五十八研究所,江苏无锡214035

出　　处：《电子设计工程》2020年第3期5-8,13,共5页Electronic Design Engineering

基　　金：国家自然科学基金资助项目(61704161)。

摘　　要：针对传统直接数字频率合成器(DDS)的频率控制字FTW必须为一个整数值,而不能为小数的情况,提出一种可编程调制的DDS电路设计。该电路结构在已有相位累加器的基础上,增加一个辅助累加器用于改变DDS内核的频率方程,使得频率控制字FTW可以是小数成为可能,提高了DDS的输出频率精度。并对传统Cordic算法进行了改进,降低了运算复杂度,减少了相幅转换的时间,节约了硬件资源。This paper proposes a programmable modulation DDS circuit design for the case where the frequency control word Ftw of the traditional direct digital synthesizer(DDS)must be an integer value,but not a decimal. The circuit structure is based on the existing phase accumulator,and an auxiliary accumulator is added to change the frequency equation of the DDS core,so that the frequency control word Ftw can be a fractional number,and the output frequency precision of the DDS is improved. The traditional Cordic algorithm is improved,which reduces the computational complexity,reduces the timeto-field conversion time,and saves hardware resources.

关 键 词：直接数字频率合成 频率控制字 精度 CORDIC算法 改进 

分 类 号：TN402[电子电信—微电子学与固体电子学]