UWB LNAs using LC ladder and transformers for input matching networks

The most efficient technique, based on LC ladder filtering, providing wide input matching in UWB LNA is first reviewed. Implemented with integrated inductors in a cascode topology, the circuit covers the 6 to 10 GHz upper frequency of European UWB and achieves an 8 dB maximum gain and 7.5 dB minimum noise figure for a 9 mW power consumption. A transformer implementation of this Inductive Degeneration LC Filtering cascode architecture is also proposed. It leads to reduce by 50% the number of integrated inductors. Providing a 13 dB maximum gain from 3 to 5 GHz, the lower band of UWB, the circuit exhibits a 4 dB minimum NF under 9 mW power consumption.