Abstract — This paper investigates the adaptive compensation of frequency response mismatches in an M-channel timeinterleaved analog-to-digital converter (TI-ADC) using an extra low-resolution ADC and a time-varying FIR filter. The introduced compensation structure may be used to compensate any linear frequency response mismatches including time skew mismatches. The coefficients of the time-varying filter are adapted using the least-mean square (LMS) algorithm. The performance of the proposed compensation structure is demonstrated through numerical simulations. I.

Gain and timing mismatches in a time-interleaved analog-todigital converter (TI-ADC) cause spurious images in its output spectrum thus effecting its performance. In this paper. we present an efficient digital blind identification structure to adaptively estimate gain and timing mismatches by using the filtered-error least-mean square (FxLMS) algorithm. The identification of mismatches helps in the removal of spurious images from the TI-ADC output spectrum and thus increases the signal-to-noise ratio (SNR). We demonstrate the performance of this structure through numerical simulations.

Abstract—In this paper, we present a flexible and scalable structure to compensate frequency response mismatches in time-interleaved analog-to-digital converters (TI-ADCs). The flexibility of the structure allows for designing compensation filters independent of the number of channels that can achieve any desired signal-to-noise ratio due to the scalability of the structure. Therefore, the compensation structure may be used to compensate time-varying frequency response mismatches in TI-ADCs, as well as to reconstruct uniform samples from nonuniformly sampled signals. We analyze the compensation structure, investigate its performance, and demonstrate application areas of the structure through numerous examples. Index Terms—Analog-to-digital converter (ADC), compensation, frequency response mismatches, reconstruction, time-interleaved, time-varying filter. I.

This paper introduces an adaptive calibration structure for the blind calibration of frequency response mismatches in a two-channel time-interleaved analog-to-digital converter (TI-ADC). By representing frequency response mismatches as polynomials, we can exploit slight oversampling to estimate the coefficients of the polynomials by using the filtered-X least-mean square (FxLMS) algorithm. Utilizing the coefficients in an adaptive structure, we can compensate frequency response mismatches including time offset and bandwidth mismatches. We develop an analytical framework for the calibration structure and analyze its performance. We show the efficiency of the calibration structure by simulations, where we include examples from the literature.