基于CORDIC算法的DDS在铷原子频标中的应用

铷原子频标是各种原子频标中发展最为活跃的,由于其独特的外在及内在的特点,使其在商业通信、空间导航等领域得到最为广泛的应用。铷原子频标中,通过DDS和倍频链共同生成Rb87原子跃迁所需的微波信号,其中带有任意尾数频率DDS的产生是非常重要的一个环节,而目前的DDS多采用查表法来实现,而对于高分辨力的DDS,查表法则需要相当巨大的ROM空间,以至于无法用于较高要求的设计中。简要介绍铷原子频标的基本原理的基础上,提出并且实现了一种基于CORDIC算法的DDS,本算法通过简单的加、减和移位等基本操作来实现DDS的功能,并给出实现DDS的实例。

Application of DDS Based On CORDIC Algorithm in Ru Atomic Frequency Standard

Rubidium frequency standard is the most active element in the development of atomic frequency standard. Because of its inherent and acquired characteristics, the rubidium clock has the fundament application in commercial communication and aerospace satellite navigation, etc. In the Rubidium frequency standard, DDS cooperates with chain of multipliers to generate microwave signal for the transition of Rb87. The introduction of fractional frequency is the prominent process of whole system. At present the implemention of DDS is mostly based on ROM which consumes high volume space in high-resolution DDS design. So it can't be used in higher design. Because of above reason, this method could not widely used . Based on the principle of Atomic Frequency Standard,This paper introduces a implemention of DDS which is based on CORDIC algorithm. this algorithm can retrieve the value of DDS by the basic process such as addition ,subtraction, shift. At last an example of DDS is presented.