A fully analog calibration technique for phase and gain mismatches in image-reject receivers

作者：Nikoofard Ali^*; Kananian Siavash; Fotowat Ahmady Ali

来源：AEU-International Journal of Electronics and Communications, 2015, 69(5): 823-835.

DOI：10.1016/j.aeue.2015.01.014

• Low-IF receivers
• I/Q mismatch calibration
• Receiver calibration
• Gain and phase mismatch
• Cognitive radio (CR)

A systematic approach to I/Q mismatch calibration in image-reject receivers is presented in this paper. A new error detection algorithm is proposed, which automatically calibrates for phase and gain mismatches limiting the performance of image-reject receivers. A dual-loop feedback is employed which looks for the minimum phase/gain error using a 2-dimensional analog-based search algorithm and then finds the minimum value for the error. An experimental CMOS prototype RF front-end for cognitive radio applications operating at 400-800 MHz is proposed and simulated in the 0.18 mu m CMOS technology, achieving an image rejection ratio (IRR) better than 55-dB in post-layout simulation. The comprehensive mathematical model of this analog algorithm is thoroughly studied in the appendix and the convergence is verified theoretically.

• 出版日期2015