A 1.8-3.1 dB noise figure (3-10 GHz) SiGe HBT LNA for UWB applications

We present the design and implementation of an ultra-wideband (UWB) silicon-germanium (SiGe) heterojunction bipolar transistor (HBT) low-noise amplifier (LNA) for use in UWB systems. The use of a shunt base-emitter capacitor and weak shunt resistive feedback in a cascode amplifier with inductive degeneration significantly improves the input bandwidth of the LNA, and allows very low noise figure to be achieved simultaneously. The LNA was fabricated in a commercially-available 0.18 /spl mu/m 120 GHz SiGe HBT BiCMOS process technology. The circuit occupies an area of 0.72 mm/sup 2/, and exhibits a record noise figure (NF) of 1.8-3.1 dB across 3.0-10.0 GHz. This SiGe LNA is very broadband, covering the entire frequency range of 0.1 to 13.6 GHz, attains a maximum gain is 20.3 dB, and operates off a 3.3 V supply with a total power consumption of 26 mW.