An　ultra-wideband　low　noise　amplifier　(UWB　LNA)　was　presented.　A　Cascode-common　base　configured　current　reuse　topology　was　employed,　and　the　power　consumption　could　be　effectively　reduced　for　direct　current,　while　the　gain　of　the　circuit　could　be　increased　for　alternating　current,　and　simultaneously　the　current-reused　topology　kept　the　advantage　of　Cascode　high　reverse　isolation.　The　spiral　inductor　of　the　output　stage　was　replaced　by　active　inductor　and　the　die　area　of　UWB　LNA　was　reduced,　and　furthermore,　the　gain　of　UWB　LNA　could　be　tunable　by　adjusting　the　effective　inductance　of　the　active　inductor.　Based　on　Jazz　0.35　μm　SiGe　BiCMOS　technology,　UWB　LNA　was　verified　with　radio　frequency　and　microwave　integrated　circuits　simulation　tools　ADS.　Results　show　that　the　improved　UWB　LNA　exhibits　the　following　performance　in　the　frequency　range　of　3.1~10.6　GHz:　the　gain　is　larger　than　14.1　dB,　the　noise　figure　is　lower　than　4.0　dB,　the　input　and　output　reflections　are　all　less　than　-10　dB,　the　input　third　order　intercept　point　is　-11　dBm　at　the　frequency　of　7　GHz,　and　the　power　is　19.75　mW.　©,　2014,　Huazhong　University　of　Science　and　Technology.　All　right　reserved.