混合滤波器组ADC通路失配偏差的校准方法

摘要

针对各采样通路之间的不匹配影响混合滤波器组ADC的重构精度这一问题,本文提出了一种校准混合滤波器组ADC通路失配偏差的模型,该模型将通路间的增益偏差、相位偏差和带宽失配偏差引入到混合滤波器组ADC中.基于此模型,建立根据输出数据求解超定方程组估算失配偏差的方法,给出引入失配偏差的混合滤波器组的结构,推导出其完美重构条件.设计实现了160MHz 12-bit的两通路混合滤波器组ADC系统,实验结果表明,提出的通路失配偏差的校准方法可提高系统的无杂散动态范围(SFDR)23dB.%The channel mismatches degrade the reconstruction performance of hybrid filter banks (HFB) analog-to-digital converters (ADC). This paper presents a comprehensive model that takes gain,phase,and bandwidth mismatches into account. Based on mis model,a method that calculates the value of the channel mismatches by solving overdetermined equations is developed. An improved architecture is introduced based on the model and the perfect reconstruction expression is derived.Finally,a two-channel 160MHz 12-bit HFB ADC system is implemented. The experimental results show that the proposed calibration technique produces about 23 dB of spurious-free dynamic range (SFDR) enhancement.