A fully integrated differential low-power low-noise amplifier (LNA) for ultrawideband (UWB) systems operating in the 3-5-GHz frequency range is presented. A two-section LC ladder input network is exploited to achieve excellent input match in a wideband fashion and to optimize the noise performance. Prototypes fabricated in a digital 0.13-mum complementary metal oxide semiconductor technology show the following performance: 9.5-dB peak power gain, 3.5-dB minimum noise figure, -6-dBm input-referred 1-dB compression point, and -0.8-dBm input-referred third-order intercept point, while drawing 11mA from a 1.5-V supply. The realized LNA is compared with previously reported LNAs tailored for the same frequency range