Low-power and low-voltage x-band silicongermanium heterojunction bipolar transistor low-noise amplifier

The power consumption of the low-noise amplifier (LNA) in radio frequency (RF) front-ends is a crucial design consideration in most wireless systems. In this study, an ultra-low-power and low-voltage LNA is implemented in a 200 nm, 150 GHz peak fT silicon-germanium (SiGe) heterojunction bipolar transistor (HBT) BiCMOS process technology. For the first time, the performance of the LNA is compared with the SiGe HBT biased in both the conventional forward-active mode and the weak-saturation (WS) mode. In the WS mode, the LNA delivers a gain of 8.5 dB at 10 GHz with a noise figure of 3.1 dB, while consuming only 0.5 mW dc power, yielding a gain per dc power consumption figure-of-merit of 17 dB/mW.