A CMOS receiver front-end for ultra-wideband (UWB) wireless communications based on multi-band OFDM -Alliance (MBOA) / WiMedia standard proposal is presented. Employing a direct conversion architecture, the RF front-end chip integrates a single-ended wideband low-noise amplifier (LNA) and two double-balanced downconversion mixers. To reduce power consumption, the conversion of single ended LNA output to differential is embedded in the RF transconductance circuit of the mixer. Fabricated in a 0.13 mu CMOS technology and housed in a low-cost QFN package, the RFIC prototype delivers a conversion gain of 19.5-23.3 dB and a noise figure of 5.2-9.1 dB over the entire 3.1-10.6 GHz UWB band, while achieving an input IP3 of -10.4 dBm and an input IP2 of 32 dBm. The RF front-end occupies only 0.9 mm active chip area and consumes 28 mA from a 1.5 V supply.