A Highly Linear Direct-Conversion Transmit Mixer Transconductance Stage with Local Oscillation Feedthrough and I/Q Imbalance Cancellation Scheme

Author

Lee, Charlotte P. ; Behzad, A. ; Ojo, D. ; Kappes, Manfred ; Au, S. ; Meng-An Pan ; Carter, Kevin ; Tian, Shiwei

Author_Institution

Broadcom, San Diego, CA

fYear

2006

fDate

6-9 Feb. 2006

Firstpage

1450

Lastpage

1459

Abstract

A linear transconductance stage with process insensitive gain control and gain insensitive output offset current is proposed. A calibration scheme to remove the LO feedthrough (LOFT) and I/Q imbalance is also introduced. The prototype achieves 3^rd-order IMD suppression better than 52dBc, LOF suppression better than 32dBc, and image rejection better than 46dBc for all gain settings. The transmit chain achieves an 802.11a EVM of < -40dB

Keywords

CMOS integrated circuits; gain control; mixers (circuits); radio transmitters; wireless LAN; 802.11a EVM; I/Q imbalance cancellation scheme; IMD suppression; LO feedthrough elmination; LOF suppression; LOFT; gain insensitive output offset current; linear direct-conversion transmit mixer stage; linear transconductance stage; local oscillation feedthrough; process insensitive gain control; Baseband; Change detection algorithms; Circuits; Envelope detectors; Gain control; Gold; Local oscillators; Radio transmitters; Transconductance; Wireless LAN;

fLanguage

English

Publisher

ieee

Conference_Titel

Solid-State Circuits Conference, 2006. ISSCC 2006. Digest of Technical Papers. IEEE International

Conference_Location

San Francisco, CA

ISSN

0193-6530

Print_ISBN

1-4244-0079-1

Type

conf

DOI

10.1109/ISSCC.2006.1696195

Filename

1696195