This paper presents an RF receiver front-end for ultra-wideband (UWB) wireless communications based on the multi-band OFDM alliance (MBOA) / WiMedia standard proposal. Fabricated in a 0.13 μm CMOS process, the receiver chip employs a direct conversion architecture and integrates a single-ended wideband low-noise amplifier (LNA) and two double-balanced downconversion mixers with embedded single-to-differential conversion. Housed in a low-cost QFN package, the IC prototype delivers a conversion power gain of 22 dB and a noise figure of 5.7 dB measured at 4 GHz, while achieving an input IP3 of-9.6 dBm and an input IP2 of 29 dBm. Consuming 31 mA from a 1.5 V supply, the receiver covers the entire UWB band from 3.1 to 10.6 GHz and occupies an area less than 1 mm2.