Highly Compact 3.1 - 10.6 GHz UWB LNA in SiGe HBT Technology

We present the design, implementation and measurement of a low noise amplifier (LNA) in a low cost 0.8 mum SiGe heterojunction bipolar technology (HBT). The measured noise figure is between 2.1 dB and 2.6 dB in the FCC-allocated bandwidth for ultra-wideband (UWB) systems. The circuit delivers 19.6 dB peak gain with gain variations of 1.3 dB within the entire band from 3.1 to 10.6 GHz. Broadband noise and power matching has been achieved with a cascode topology using resistive shunt feedback in combination with a diode DC level shifter. The measured input IPS is -14.1 dBm with 10.3 mA total current from a 3.5 V supply. All performance characteristics are comparable to the best reported UWB LNAs but come at a drastically smaller occupied die area of 0.13 mm².