【作者】 王骞； 蔡逢煌； 王武； 王英俊；

【Author】 WANG Qian,CAI Fenghuang,WANG Wu,WANG Yingjun (College of Electrical Engineering and Automation,Fuzhou University,Fuzhou 350108,China)

【机构】 福州大学电气工程与自动化学院；

【摘要】 在采用∑-△调制器结构的音频模数转换系统中,针对调制器中积分器参数不确定性对系统输出性能的影响,提出一种改进型的五阶2-2-1级联∑-△调制器,并研究∑-△调制器中鲁棒滤波器的设计问题。基于MARKOV区间算法,将不确定性因子间的非线性关系表述为线性区间矩阵,并以线性矩阵不等式给出鲁棒滤波器存在的充分条件。最后采用优化CSD编码设计了鲁棒滤波器。仿真结果表明,鲁棒滤波器比传统滤波器的输出信噪比提高了20 dB,可达到114.5 dB的信噪比和18.72位的精度;该方法具有实现成本低、资源占用少的优点,可应用于音频模数转换器。更多还原

【Abstract】 In the audio analog to digital converter system using sigma-delta modulator structure,an improved fifth-order 2-2-1 cascaded sigma-delta modulator and robust filter was studied to solve the restriction of the uncertainty of integrator parameter to the cascaded sigma-delta modulator.Based on MARKOV interval algorithm,the nonlinear relationship of uncertain factors was transformed into linear interval matrix.A linear matrix inequality approach was developed to obtain the parameters of a robust filter.The robust filter was designed based on method of optimized CSD coding.The results indicate that the robust filter outperformed the nominal filter with an improve signal-to-noise ratio about 20 dB,which achieves a signal-to-noise ratio of 114.5 dB and a resolution of 18.72 bits.The robust filter has the advantage of low cost and little using of resource.This filter is sufficient for the audio analog to digital converter applications.更多还原