Title :
Digital Adaptive IIP2 Calibration Scheme for CMOS Downconversion Mixers
Author :
Dufrêne, Krzysztof ; Boos, Zdravko ; Weigel, Robert
Author_Institution :
Inst. for Electron. Eng., Univ. Erlangen-Nuremberg, Erlangen
Abstract :
This paper presents a cancellation scheme of second order intermodulation distortion based on adaptive digital calibration of the RF downconversion mixer. The system utilizes a low-complexity LMS-based equalizer, which correlates differential mode distortion with common mode distortion to estimate optimum settings of the analog IP2 calibration circuit. A tunable IQ mixer prototype, fabricated in a 0.13 mum RF CMOS technology and operating under low voltage supply of 1.5 V, is presented. Experimental results confirm the feasibility of the proposed IP2 calibration method.
Keywords :
CMOS integrated circuits; adaptive equalisers; calibration; intermodulation distortion; least mean squares methods; low-power electronics; mixers (circuits); radiofrequency integrated circuits; CMOS downconversion mixers; RF CMOS technology; RF downconversion mixer; analog IP2 calibration circuit; cancellation scheme; differential mode distortion; digital adaptive IIP2 calibration scheme; low voltage supply; low-complexity LMS-based equalizer; second order intermodulation distortion; size 0.13 mum; tunable IQ mixer prototype fabrication; voltage 1.5 V; 1f noise; Band pass filters; CMOS technology; Calibration; Filtering; Integrated circuit technology; Intermodulation distortion; Radio frequency; Receivers; Tunable circuits and devices; Adaptive circuits; CMOS analog integrated circuits; DC offset; IIP2; calibration; direct conversion; intermodulation distortion; least mean square methods; mismatch; mixers; radio receivers; second-order distortion;
Journal_Title :
Solid-State Circuits, IEEE Journal of
DOI :
10.1109/JSSC.2008.2005453
