An inductorless Ultra-Wide Band (UWB) receiver front-end chip design used in wireless communications for the frequency band of 3.1～4.8 GHz is presented. This homodyne receiver mainly consists of a differential Low Noise Amplifier (LNA) circuit followed by a down-converting mixer. The proposed LNA circuit with a noise canceling resistor is connected to the CMOS device's body to reduce the substrate thermal noise. Simulation and measurement results show that the chip can reduce the front-end Noise Figure (NF) about 0.5dB and achieve the Conversion Gain (CG) of 19.44～21.57 dB and double-sideband NF less than 7.8 dB. Also, the input third-order intercept point (IIP3) is -11 dBm, and the input second-order intercept point (IIP2) is 49 dBm. Fabricated in TSMC 0.18 μm CMOS technology, this chip occupies only 0.167 mm2 and dissipates power 59.2 mW.