Title
Correlation-Based Calibration for Nonlinearity Mismatches in Dual-Channel TIADCs
Abstract
Mismatches affect the dynamic performance of time-interleaved analog-to-digital converters (TIADCs). Linear mismatches can be calibrated by many mature methods, but if higher performance is required, nonlinearity mismatches have to be suppressed. The background calibration method based on input-free band (IFB) functions poorly for narrow-band signals. This paper proposes a correlation-based calibration method for nonlinearity mismatches in dual-channel TIADCs which behaves well for both wide-band and narrow-band signals. The output samples are calibrated by reducing the residual distortions which are approximated by multiplying the pseudo distortions and the estimated mismatch coefficients. The pseudo distortions are acquired by using a frequency-shifter, a differentiator, and multipliers. The coefficients which indicate the mismatch strength are estimated by eliminating the cross-correlation of the calibrated output samples and the calibrated pseudo distortions at zero lag. Simulations show that the proposed method can improve the SFDR by dozens of dBc for narrow-band input signals, compared with the input-free band method. For the 16-QAM signal, the EVM improvement over the IFB method is 35.48 dB.
Year
DOI
Venue
2020
10.1109/ISCAS45731.2020.9180462
2020 IEEE International Symposium on Circuits and Systems (ISCAS)
Keywords
DocType
ISBN
Calibration,Distortion,Analog-digital conversion,Electrical engineering,Correlation,Estimation,Circuits and systems
Conference
978-1-7281-3320-1
Citations 
PageRank 
References 
0
0.34
0
Authors
5
Name
Order
Citations
PageRank
Xiangyu Liu15114.10
Hui Xu201.01
Yinan Wang3279.85
Nan Li42828.52
Håkan Johansson501.01