A low supply voltage SiGe LNA for ultra-wideband frontends

A low-power low-noise amplifier (LNA) for ultra-wideband (UWB) radio systems is presented. The microwave monolithic integrated circuit (MMIC) has been fabricated using a commercial 0.25-μm silicon-germanium (SiGe) bipolar CMOS (BiCMOS) technology. The amplifier uses peaking and feedback techniques to optimize its gain, bandwidth and impedance matching. It operates from 3.4 to 6.9 GHz, which corresponds with the low end of the available UWB radio spectrum. The LNA has a peak gain of 10 dB and a noise figure less than 5 dB over the entire bandwidth. The circuit consumes only 3.5 m W using a 1-V supply voltage. A figure of merit (FoM) for LNAs considering bandwidth, gain, noise, power consumption, and technology is proposed. The realized LNA circuit is compared with other recently published low-power LNA designs and shows the highest reported FoM.