Design of a fully differential CMOS LNA for 3.1-10.6 GHz UWB communication systems

A fully differential complementary metal oxide semiconductor (CMOS) low noise amplifier (LNA) for 3.1-10.6 GHz ultra-wideband (UWB) communication systems is presented. The LNA adopts capacitive cross-coupling common-gate (CG) topology to achieve wideband input matching and low noise figure (NF). Inductive series-peaking is used for the LNA to obtain broadband flat gain in the whole 3.1-10.6 GHz band. Designed in 0.18 μm CMOS technology, the LNA achieves an NF of 3.1-4.7 dB, an S11 of less than -10 dB, an S21 of 10.3 dB with ±0.4 dB fluctuation, and an input 3rd interception point (IIP3) of -5.1 dBm, while the current consumption is only 4.8 mA from a 1.8 V power supply. The chip area of the LNA is 1×0.94 mm2.