Abstract: This paper proposes a distributed amplifier which can be applied to ultra wide-band (UWB) wireless communication systems. The distributed amplifier can realize the bandwidth extension by using artificial transmission line formed by inductors to absorb parasitic capacitances of the transistors. Benefiting from the wealth of distributed theory, the proposed low noise amplifier (LNA) not only extends its bandwidth but also maintain a low noise figure during operation wideband. This circuit has been designed under TSMC RF 0.18 μm 1P6M process with 1.8 V supply, and the power consumption is 104 mW. Simulation results show that the designed LNA has a flat gain of 18.7 dB from 2.9 GHz to 10.6 GHz with less than 0.9 dB ripple and its minimum noise figure (NF) is only 1.80 dB.