Compact Variable Gain Amplifier for a Multistandard WLAN/WiMAX/LTE Receiver
2014 (English)In: IEEE Transactions on Circuits and Systems Part 1: Regular Papers, ISSN 1549-8328, Vol. 61, no 1, 247-257 p.Article in journal (Refereed) Published
This paper presents a novel single-stage VGA architecture that employs two Gm cells, a voltage-controlled current attenuator, resistors and capacitors. The gain can be changed in three large steps by using digital controls, and continuously within these steps. The VGA bandwidth and output-related IP3 and 1dBCP are independent of the gain setting; the bandwidth can be programmed through a digitally-controlled capacitor array placed at its output. The proposed architecture was employed to realize the VGA for a WLAN/WiMAX/LTE radio receiver. Die area and power consumption were reduced by implementing the two Gm cells with one instantiation of a high-linearity Gm-core and scaled outputs; also, the current attenuator was implemented with a simple differential current steering circuit; finally, the load resistors were also used to sense the output common-mode level. The VGA was fabricated in 0.15 um standard CMOS process. Measurement results show the gain varying between 5 dB to 30 dB and the max bandwidth surpasses 60 MHz; 11.14 nV/root Hz input referred noise; O1dBCP of 8.6 dBm while taking 4.2 mA from a 1.8 V supply; it settles within 20 ns after a min-max step-change of the gain; it occupies 0.05 mm(2).
Place, publisher, year, edition, pages
2014. Vol. 61, no 1, 247-257 p.
LTE, multistandard receiver, programmable bandwidth, variable gain amplifier, WiMAX, WLAN
Electrical Engineering, Electronic Engineering, Information Engineering
IdentifiersURN: urn:nbn:se:kth:diva-141307DOI: 10.1109/TCSI.2013.2268324ISI: 000330037500023ScopusID: 2-s2.0-84892572083OAI: oai:DiVA.org:kth-141307DiVA: diva2:696551
QC 201402142014-02-142014-02-132014-02-14Bibliographically approved