Design of Magnitude Preserving Analog-to-Digital Converter

Antonio PETRAGLIA  Sanjit K. MITRA  

IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences   Vol.E76-A   No.2   pp.149-155
Publication Date: 1993/02/25
Online ISSN: 
Print ISSN: 0916-8508
Type of Manuscript: INVITED PAPER (Special Section on High-Speed Analog Circuits and Signal Processing)
A/D converters,  filter banks,  

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A new type of analog-to-digital (A/D) converter is introduced. The structure is based on a magnitude-preserving quadrature mirror filter (QMF) bank where the analysis bank is composed on IIR switched-capacitor (SC) filters. The analog output samples of the analysis filters are converted into digital form using individual A/D converters and combined by an IIR digital filter synthesis filter bank. This A/D converter is useful in applications where only the magnitude of the spectrum of the analog signal needs to be preserved. The structure incorporates the advantages of sub-band coding and reduces considerably the effect of mismatches among the sub-band A/D converters. In addition, the proposed scheme leads to an increase in the conversion speed by a factor of M when an M-channel QMF bank is used. An illustrative example verifying the good performance of the proposed approach is included.