A concurrent multiband InGaP-GaAsHBT LNA for 1.8/1.9-GHz GSM, 2.4/4.9/5.2/5.7-GHz WLAN, and 5-7-GHz ultra-wideband (UWB) system applications

[[abstract]]A temperature-insensitive (-25 degrees C-175 degrees C) monolithic concurrent multiband low-noise amplifier (LNA) for 1.8/1.9-GHz GSM, 2.4/4.9/5.2/5.7-GHz WLAN, and 5-7-GHz ultra-wideband (UWB) system applications is realized using a low-cost 2-mu m InGaP-GaAs HBT technology. The first stage of the LNA provides high gain and input matching simultaneously at the 1.8/1.9-GHz GSM, 2.4/4.9/5.2/5.7-GHz WLAN, and 5-7-GHz UWB bonds. The output matching of the second stage was realized by using shunt-shunt feedback. It consumes only 9-mW power and achieves transducer gains (S-21) of 27.2, 27.1, 24.9, 16.2, 16.0, 15.2, and 11.5 dB; reverse isolation (S-21) of -46.4, -47.4, -47.4, -45.2, -44.6, -43.1, and -43.4 dB; input return losses (S-11) of -13, -14.8, -22.8, -10, -17, -27.7, and -10 dB, output return losses (S-22) of -11.4, -11.5, -14.2, -17.6, -17.3, -19.4, and -19.4 dB, and noise figures of 1.99, 2.06, 3.06, 3.22, 2.8, 2.22, and 2.33 dB at 1.8, 1.9, 2.4, 4.9, 5.2, 5.7, and 7.0 GHz, respectively. To our knowledge, the noise figures (2.22 dB at 5.7 GHz and 2.33 dB at 7 GHz) are state-of-the-art results among all C-band bipolar LNAs with a fully on-chip input matching network. The LNA only occupies an area of 650 X 300 mu m, excluding the test pads because only two inductors are used. (c) 2005 Wiley Periodicals, Inc.[[note]]SC