宽带CIC抽取滤波器的一种改进方法  

Improved Method for Wideband CIC Decimation Filters

作　　者：姚远程[1] 蔡晓丽[1] 李湘鲁[2] 黄嵩[1] 

机构地区：[1]西南科技大学信息工程学院,四川绵阳621010 [2]中国工程物理研究院电子工程研究所,四川绵阳621900

出　　处：《电子科技大学学报》2012年第2期208-211,226,共5页Journal of University of Electronic Science and Technology of China

基　　金：国家自然科学基金NSAF联合基金(10876035)

摘　　要：经典CIC抽取滤波器处理宽带信号时幅频响应不理想,满足带外衰减指标时,通带衰减过大,难以满足抗混叠性能要求。针对该问题,提出了一种改善性能的方法,在已有的分级抽取滤波器的基础上利用锐化技术提高滤波器阻带衰减,并利用补偿滤波器在采样率降低后对通带进行额外补偿,减少计算量的同时使带内更平坦。仿真分析表明,改进后的滤波器的通带衰减度均大于0.002 dB,阻带衰减小于57 dB,抗混叠性能优良。The decimation filters of better performance is demanded in multi-rate process when wideband signal with high sample rate is processed by digital IF receiver.The frequency response of classic CIC decimation filters does not meet the requirement when it process wideband signal.The problem is that it has to increase pass-band attenuation to achieve the necessary stop-band attenuation with poor alias rejection.For solving the problem,the paper proposes an improved method which improves alias rejection by taking advantage of sharpening technique on the two-stage comb filter,and applies compensator filters in low sample rate with low computation to improve pass-band characteristics.The simulation result indicates that pass-band attenuation of proposed filter is over than-0.002dB,stop-band attenuation is less than-57dB,and anti-aliasing performance is better.

关 键 词：算法 数字滤波器 多速率处理 锐化技术 

分 类 号：TN911[电子电信—通信与信息系统]