Title :
Codesign of Mixer-VGA Downconverter Blocks
Author :
Fan Jiang ; Saavedra, Carlos E.
Author_Institution :
Queen´s Univ., Kingston, ON, Canada
Abstract :
Two radio frequency integrated circuit (RFIC) downconverters are presented, each consisting of an active mixer and a variable gain amplifier (VGA). The downconverter blocks (DCBs) have identical mixing stages but different VGA topologies. The mixers use a commutating switching network and a low-noise RF transconductance stage to reduce the system noise figure (NF). VGA gain control in one DCB (DCB-1) is done using a current-steering approach, while the second DCB (DCB-2) employs a transistor-based attenuator. Both RFICs were designed and fabricated using a standard 130-nm CMOS process and they were tested over the RF band covering 1-6 GHz and at an IF of 140 MHz. Measurements show that the conversion gain (CG) of DCB-1 ranges from 9.6 to 25.3 dB, and for DCB-2, the CG ranges from 10.7 to 23.7 dB. The minimum double-sideband NF for both the downconverters is 3.8 dB but their maximum NFs are different: 1) 14.2 dB for DCB-1 and 2) 11.5 dB for DCB-2.
Keywords :
CMOS integrated circuits; UHF mixers; amplifiers; field effect MMIC; gain control; microwave mixers; radiofrequency integrated circuits; CMOS process; RFIC; active mixer; commutating switching network; current-steering approach; frequency 1 GHz to 6 GHz; frequency 140 MHz; gain 9.6 dB to 25.3 dB; gain control; low-noise RF transconductance; mixer-VGA downconverter blocks; radiofrequency integrated circuit; size 130 nm; transistor-based attenuator; variable gain amplifier; Frequency measurement; Gain; Mixers; Noise measurement; Radio frequency; Voltage control; Voltage measurement; Amplifier; CMOS; Gilbert cell; IIP3; attenuator; conversion gain (CG); current bleeding; digitally assisted; downconverter; low noise; microwaves; mixer; noise canceling; radio frequency integrated circuit (RFIC); receiver; steering; variable gain; variable gain amplifier (VGA);
Journal_Title :
Electrical and Computer Engineering, Canadian Journal of
DOI :
10.1109/CJECE.2015.2416117