A 2-20 GHz SiGe HBT single-stage cascode LNA with linearity enhancement

摘要

A wideband high-gain low-noise amplifier (LNA) with improved linearity is presented in this paper. To suppress the gain compression of large signal under high gain conditions, the single-stage cascode topology using resistive shunt-shunt feedback and an emmiter degenerate resistor are adopted. Wideband input matching is thus realized in conjunction with the preceding L-type passive network. A passive network inserted between the cascode structure and load enhances the gain bandwidth as well as the impedance matching. The LNA is based on a 0.18 mu m SiGe HBT BiCMOS process and the post simulation results show that the LNA features 2-20 GHz band-width, 16.1-18.1 dB power gain and 2.5-3.7 dB noise figure (NF). It exhibits input 1-dB compression point of -12dBm above 14 GHz and consumes 55 mW power form a 3.3-V supply. The chip size is 0.435 mm(2) without pads.