A New Linearization Technique for CMOS RF Mixer Using Third-Order Transconductance Cancellation

• Published in: IEEE microwave and wireless components letters Vol. 18; no. 5; pp. 350 - 352
• Main Authors: LIANG, Kung-Hao, LIN, Chi-Hsein, CHANG, Hong-Yeh, CHAN, Yi-Jen
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01.05.2008; Institute of Electrical and Electronics Engineers
• Subjects: Applied sciences; Cancellation; Circuit properties; Circuits; CMOS; CMOS technology; Design. Technologies. Operation analysis. Testing; Devices; Distortion measurement; Electric, optical and optoelectronic circuits; Electronic circuits; Electronics; Exact sciences and technology; harmonic; Integrated circuits; intermodulation; Intermodulation distortion; Linearity; linearization; Linearization techniques; mixer; Mixers; Noise levels; Power measurement; Radio frequencies; Radio frequency; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Signal convertors; third-order intermodulation (IMD3); third-order transconductance; Transconductance; Transistors; Voltage; Harmonic; Intermodulation distortion; Radio wave; Third order; Mixer; Transistor; Adjacent channel; Radiofrequency; Non linear phenomenon; third-order intermodulation (IMD3); third-order transconductance; CMOS; Complementary MOS technology; Linearity; Intermodulation; Non linear effect; Frequency mixing; Transconductance; Linearization
• ISSN: 1531-1309; 1558-1764
• DOI: 10.1109/LMWC.2008.922129

A new third-order transconductance (g m3 ) cancellation technique is proposed and applied to a conventional radio frequency (RF) mixer for improving circuit linearity. The bulk-to- source voltage is applied to adjust the peak value position of gms. The cancellation of g m3 is utilized by a negative peak g m3 transistor combined in parallel with a positive peak g m3 transistor. For a single device, the measured adjacent channel power ratio (ACPR) and third-order intermodulation (IMD3) distortion are both improved over 15 dB. A Gilbert-cell mixer in commercial 0.18-mum CMOS process was designed using the proposed method to further evaluate the linearity. The compensated g m3 device is placed in the input RF gm-stage and then reducing the principle nonlinearity source of the mixer. From the experiment results, the ACPR and IMD3 of the mixer are improved about 10 and 15 dB, respectively.