基于DDS和DSM的多通道信号源的设计与实现  

Design and Implementation of DDS and DSM-based Multi-channel Signal Sources

作　　者：陈洋[1] 管国云[1] 聂在平[1] 

机构地区：[1]电子科技大学电子工程学院,四川成都611731

出　　处：《测井技术》2013年第1期75-79,共5页Well Logging Technology

基　　金：国家自然科学基金项目No.60931004资助

摘　　要：介绍基于DDS和DSM技术的多通道高精度正余弦信号发生器的实现架构。采用基于FPGA的直接数字频率合成(DDS)技术,实现高质量多路正余弦信号源的产生,有效降低硬件资源消耗。该架构时分复用(TDM)基于FPGA实现的旋转坐标数字计算机(CORDIC)算法的16级CORDIC流水线实现多路正余弦信号发生器,采用五阶1bit Delta Sigma调制器(DSM)实现1bit DAC以保证信号高精度的最终输出。当信号频率为200kHz时,测量信噪比(SNR)为78.6dB,完全可以满足测量系统中对信号源频谱纯度的要求。设计尤其适用于低频高精度多通道正余弦信号源的应用场合,可以有效简化多路信号的设计,降低实现成本。Introduced is DDS and DSM-based multi-channel high-precision sine and cosine signal generator architecture. The FPGA direct digital frequency synthesis （DDS） technology is used to generate high quality multiple channel signal sources, which at the sametime effectively reduces the hardware resources consumption. The architecture includes TDM-based CORDIC sine and cosine waves generator, 1 bit Delta Sigma modulator （DSM） DAC and analog low-pass filter. To realize 14 bit precision, the CORDIC uses 16 stages of pipelined design, so the SNR is about 80 dB. The 5th-order 1 bit DSM is used to implement 1 bit DAC so as to ensure the final output signal precision. When the output frequency is 200 kHz, the measured SNR is 78.6 dB, which meets the requirement of spectrum purity of the four-channel signal sources. The above design is particularly suitable for high-precision multi-channel sine and cosine signal source in the low frequency domain, and effectively simplifies the design of multi-channel signal while reducing the costs.

关 键 词：直接数字频率合成 多通道信号源 旋转坐标数字计算机 DELTA Sigma调制器 

分 类 号：P631.84[天文地球—地质矿产勘探]