High speed A/D conversion using QMF banks

A structure for analog-to-digital (A/D) conversion capable of attaining high resolution and high speed using lower-resolution, lower-speed A/D converters is presented. The structure is based on quadrature mirror filter (QMF) banks, except that the analysis filter bank is a switched-capacitor circuit whereas the synthesis bank is a digital filter circuit. The structure incorporates the advantages of subband coding, and considerably reduces the effect of mismatches among the low-resolution A/D converters. An illustrative example and experimental results verifying the good performance of the proposed approach are included