A Polynomial-Based Time-Varying Filter Structure for the Compensation of Frequency-Response Mismatch Errors in Time-Interleaved ADCs

• Published in: IEEE journal of selected topics in signal processing Vol. 3; no. 3; pp. 384 - 396
• Main Author: Johansson, H.
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.06.2009; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Analog-digital conversion; Approximation; Channels; Compensation; Delay; Differentiators; Digital filters; Errors; Frequency conversion; Frequency dependence; Frequency-response mismatch errors; Interleaved codes; Multipliers; On-line systems; polynomial impulse responses; Polynomials; Sampling methods; TECHNOLOGY; TEKNIKVETENSKAP; Temperature; Time varying systems; time-interleaved analog-to-digital converters; time-varying compensation filters
• ISSN: 1932-4553; 1941-0484
• DOI: 10.1109/JSTSP.2009.2020554

This paper introduces a structure for the compensation of frequency-response mismatch errors in M-channel time-interleaved analog-to-digital converters (ADCs). It makes use of a number of fixed digital filters, approximating differentiators of different orders, and a few variable multipliers that correspond to parameters in polynomial models of the channel frequency responses. Whenever the channel frequency responses change, which occurs from time to time in a practical time-interleaved ADC, it suffices to alter the values of these variable multipliers. In this way, expensive on-line filter design is avoided. The paper includes several design examples that illustrate the properties and capabilities of the proposed structure.