改进的一阶1 bit Sigma-Delta调制器研究

Study on improved one-order Sigma-Delta modulator with single bit

为了改善量化噪声,提出了一种新的一阶1 bit Sigma-Delta调制器结构。通过对标准的一阶1 bit SigmaDelta调制器进行研究,指出了其量化噪声是非加性的,并且把输入和输出之差作为Sigma-Delta调制器的输入,进一步实现了输入信号的调制。理论推导得出新结构对正弦信号调制的信噪比比传统结构高6 dB,MATLAB Simulink仿真结果显示新结构带内噪声功率减小,为高性能的Sigma-Delta调制器提出了一种新的设计方法。

This paper proposed a new one-order 1 bit Sigma-Delta modulator（ NSDM） in order to improve the feature of quantization noise. It pointed out that the feature of quantization noise was not additive through analysing the feature of quantization noise,and put the difference of input and output as the input of SDM to further modulate the input signal. Theoretically,it derive that NSDM has higher SNR than SDM about 6 dB for modulating the sinusoidal signal. The simulation results show that the new structure noise power is reduction. It provides a new design method for SDM with high performance.