基于线性插值的DDFS中的相位-幅度映射研究  

A Study on Phase-to-amplitude Mapping in DDFS Based on Linear Interpolation

作　　者：何方勇[1] 陈建安[1] 

机构地区：[1]西安电子科技大学电子工程学院,西安710071

出　　处：《现代雷达》2006年第1期71-75,共5页Modern Radar

摘　　要：提出了采用线性插值的方法来实现直接数字频率合成器(DDFS)结构中相位到正弦曲线幅度之间的映射(简称“相幅映射”)。该方法使用具有分段连续性质的线性分段来近似正弦函数曲线的第一象限部分;然后根据正弦曲线的象限对称性,重构完整的正弦曲线。文中分析了基于线性插值技术的DDS的频谱特性;然后对基于该方法的DDS的“无杂散动态范围”进行了研究。最后,提出了线性插值系数选择的详细、系统的步骤,从而取得期望的SFDR。This paper presents an approach based on linear interpolation to realize the mapping from phase to sinusoid amplitude （phase-to-amplitude） in the structure of direct digital frequency synthesizers （DDFS）. For that approach, the first quadrant of the sine function is approximated with a number of linear segments, then the sine funetian is fully reconstructed by using its symmetry. This paper provides the analysis of spectrum in DDFS based on linear interpolation technology. Then the spurious free dynamic range （SFDR） is also studied for DDFS based on this approach. At last, a detailed and systematic procedure for the selection of linear segment coefficients to achieve a desired SFDR is provided.

关 键 词：直接数字频率合成器 无杂散动态范围 SFDR 线性插值 相幅映射 

分 类 号：TN74[电子电信—电路与系统]