An Adaptive Blind Calibration Technique for Frequency Response Mismatches in M-Channel Time-Interleaved ADCs

Abstract

This brief proposes a novel adaptive architecture for blind estimation and calibration of the frequency response mismatches in an M-channel time-interleaved analog-to-digital converter (TI-ADC). Based on the basis functions generated from the measured TI-ADC output, the mismatch errors could be reconstructed blindly and subtracted from the TI-ADC output adaptively. The advantage of the proposed technique is that it only needs to know the measured output signal without requiring any additional information and it is applicable to any channel TI-ADCs. Specially, the calibration structure only needs several differentiators with fixed coefficients without requiring a bank of adaptive FIR filters. In addition, the numerical simulations have been presented to demonstrate the effectiveness and superiority of the proposed technique, which shows that the proposed technique can improve the SNR and SFDR by over 25 dB.