Ultra-Low-Power X-band SiGe HBT Low-Noise Amplifiers

The performance of four low power X-band low-noise amplifier (LNA) topologies implemented in a 0.18 mum SiGe BiCMOS technology is compared. All versions are fully integrated and designed to achieve a gain of 15 dB and a noise figure of 2.5 dB with a power consumption in the 1-3mW range. For a broadband cascode LNA, a gain of 16-18 dB, a noise figure of 3.5 dB and an input 1P3 of -16 dBm is achieved over a wide bandwidth from 7 GHz to 12 GHz for an associated power consumption of 1.8 mW. For the same power consumption, a cascode LNA optimized for narrowband exhibits a gain of 17 dB, a noise figure of 2.5 dB. This LNA also achieves a gain of 10 dB and 3.6 dB noise figure for an associated power consumption of only 0.8 mW. These values are the best reported X-band gains per mW DC power reported in any technology.