IIP2 and DC Offsets in the Presence of Leakage at LO Frequency

Author

Elahi, Imtinan ; Muhammad, Khurram ; Balsara, Poras T.

Author_Institution

Texas Instruments Inc., Dallas, TX

Volume

53

Issue

8

fYear

2006

Firstpage

647

Lastpage

651

Abstract

Device mismatch in a mixer is generally believed to be the major contributor of second-order distortion that limits the performance of a direct conversion receiver. In this brief, we show that even with perfect matching, leakage at local oscillator frequency prior to mixing creates large second-order distortion when the third-order input intercept point of the receiver is not sufficiently large. Measurement data from a quad-band global system for mobile communications/global packet radio service transceiver implemented in 90-nm digital CMOS process is also presented to support our claim

Keywords

CMOS integrated circuits; distortion; mixers (circuits); mobile communication; packet radio networks; radiofrequency interference; radiofrequency oscillators; signal processing; transceivers; 90 nm; DC offsets; DCR; IIP2; IIP3; LO frequency; digital CMOS process; direct conversion receiver; global packet radio service transceiver; local oscillator frequency leakage; local oscillator leakage; mixer device mismatch; mobile communications; quad-band global system; second-order distortion; second-order input intercept point; third-order input intercept point; Band pass filters; CMOS process; Circuits; Frequency; GSM; Local oscillators; Nonlinear distortion; RF signals; Radiofrequency amplifiers; Receivers; DC offsets; direct conversion receiver (DCR); local oscillator (LO) leakage; second-order input intercept point (IIP2); third-order input intercept point (IIP3);

fLanguage

English

Journal_Title

Circuits and Systems II: Express Briefs, IEEE Transactions on

Publisher

ieee

ISSN

1549-7747

Type

jour

DOI

10.1109/TCSII.2006.876469

Filename

1683973