任意函数发生器的相位截断对数字合成信号影响的分析  

Analysis of the Effects on Digitally Synthesized Signals of Arbitary Function Generator due to Phase-accumulator Truncation

作　　者：李春明[1] 宁岩 孙圣和[1] 

机构地区：[1]哈尔滨工业大学无线电工程系,哈尔滨150001 [2]黑龙江省技术物理研究所,哈尔滨150080

出　　处：《电子测量与仪器学报》1997年第2期1-6,共6页Journal of Electronic Measurement and Instrumentation

摘　　要：在任意函数发生器中，相位累加器的相位截断效应使合成信号中含有寄生噪声，降低了合成信号的信噪比。本文利用非均匀取样模型和数字频谱分析方法研究了相位截断对数字合成任意信号的影响，给出了合成信号的数字频谱及信噪比的一般表达式，并讨论了存在相位截断时的相位累加器位数、波形存储器容量及频率控制字与合成信号序列输出信噪比之间的关系。This paper presents an analysis of output spectra of arbitrary function generator in the presence of phase-accumulator truncation. With digital spectrum analysis technology, a closed form expression is derived which relates the magnitude, number and position of the spu-rious noise lines in the output spectra to the waveform memory size, the amount of phase accu-mulator truncation and frequency control word. Furthermore, we derive the signaLto-noise ra-tio of digitally synthesized signals due to the truncation. This investigation is helpful to the de-sign and the analysis of arbitrary function generator and digital frequency synthesizer.

关 键 词：数字波形合成 函数发生器 寄生噪声 相位截断 

分 类 号：TP332.2[自动化与计算机技术—计算机系统结构]