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 mm,a.