A concurrent multiband SiGe LNA for 1.8/1.9-GHz GSM, 2.4/5.2/5.7GHz WLAN, and 5-7-GHz ultrawideband (UWB) system applications

[[abstract]]A concurrent multiband low-noise amplifier (LNA) for 1.811.9-GHz GSM, 2.415.215.7-GHz WLAN, and 5-7-GHz ultra-wideband (UWB) system applications is realized using 0.35-mu m SiGe BiCMOS technology. The LNA occupies an area of only 600 X 300 Am, excluding the test pads, because only two inductors are used. The first stage of the LNA provides high gain and input matching simultaneously at the 1.8/1.9-GHz GSM and 2.4/5.2/5.7-GHz WLAN bands. The output matching of the second stage is realized by shunt-shunt feedback. It consumes only 14.4-mW power and achieved transducer gains (S-21) of 26.6, 26.3, 24.6, 15.8, and 14.8 dB, input return losses (S-11) of -8.4, -9.9, -22.4, -12.3, and - 17.1 dB, noise figures of 1.81, 1.9, 2.41, 3.4, and 2.81 dB (for fully on-chip input matching), and noise figures of 1.5, 1.6, 2.0, 2.82, and 2.32 dB (for off-chip input matching) at 1.8, 1.9, 2.4, 5.2, and 5.7 GHz, respectively. In addition, very low and very flat NF versus frequency characteristics (below 3.0 dB) are achieved over a very wide frequency range (from 5 to 7.2 GHz), which means the implemented LNA is also very suitable for 5-7-GHz UWB-system applications. (c) 2005 Wiley Periodicals, Inc.[[note]]SC