基于群延迟优化的IIR数字滤波器设计  

IIR Digital Filter Design Based on Group Delay Optimization

作　　者：蒋铁珍[1] 肖凯[1] 崔永昕 吴文俊 秘晨阳 JIANG Tie-zhen;XIAO Kai;CUI Yong-xin;WU Wen-jun;MI Chen-yang(School of Integrated Circuits,Anhui University,Hefei 230601,China)

机构地区：[1]安徽大学集成电路学院,安徽合肥230601

出　　处：《中国电子科学研究院学报》2023年第10期882-888,共7页Journal of China Academy of Electronics and Information Technology

摘　　要：针对IIR数字滤波器位于通带的频率相量延迟不同的时间量,提出了一种群延迟优化方法。对于级联型IIR滤波器系统,该方法在每一级滤波器后接入一个全通滤波器,对设计完成的全通滤波器进行零极点分析,通过分析零极点在z平面的位置,评估全通滤波器以及整个数字滤波器级联情况的稳定性。仿真实验采用8阶的巴特沃斯低通滤波器,在0~150 Hz的通带范围内,采样率48 kHz,群延迟优化采用一阶的全通滤波器,仿真结果显示该方法将群延迟的变化量在原有的系统上优化了49.58%。对比其他主流的方法,本文的方法具有计算量小和易于实现的优点。A group delay optimization method is proposed to solve the problem that the frequency phasor of IIR digital filters in the passband delays different time quantities.For the cascaded IIR filter system,the end of each filter stage is connected to an all-pass filter.Zero and pole analysis is performed on the designed all-pass filter,and stability of the all-pass filter and entire digital filter cascade is evaluated by analyzing position of the zero and pole in the z-plane.In the simulation and experimental part,8-order Butterworth low-pass filter in the passband range of 0~150 Hz is adopted,and sampling rate is 48 kHz.Besides,the first-order all-pass filter is adopted in the group delay optimization.Simulation results show that the change amount of group delay is optimized by 49.58%on original system.The proposed algorithm has the advantages of less computation and convenient implementation in comparison with other mainstream methods.

关 键 词：数字滤波器 群延迟 级联型 全通滤波器 巴特沃斯低通滤波器 

分 类 号：TN431.2[电子电信—微电子学与固体电子学]