Indoor positioning technology is becoming more and more widely deployed in recent years.An important technology trend for mobile communication terminals is that Ultra-WideBand (UWB) transceiver SoCs (System-on Chips) being integrated into the system to support indoor positioning.As a key building block in UWB transceivers, the Low Noise Amplifier (LNA) is of full challenges to design mainly due to the full-band (3.1-10.6 GHz) coverage, wide-band input matching and flat Noise Figure (NF) requirements.Conventional LNA topologies typically suffer from severe compromise among noise figure, gain and input matching, resulting in very limited Figure of Merit (FoM).This paper presents a two-stage LNA for UWB application.The first stage is based on transformer-feedback input matching while the second stage employs multi-functional output driver, achieving flat NF and high gain.Designed in TSMC 65 nm CMOS, simulation results show that the LNA achieves S₁₁<-10 dB, gain >17 dB, NF of 2.71±0.28 dB, and 1 dB compression point of -17.5 dBm while consuming 32.8 mW from a 1.2 V supply, corresponding to FoM-I of 2.32 and FoM-II of 0.41, respectively.