In order to satisfy the demands of wireless receiver of 3.5 GHz sole-carrier UWB communication system

an ultra-wideband 3 ～4 GHz low noise amplifier is presented.The circuit is implemented in CMOS common-gate differential structure

using capacitor cross-coupling structure and noise canceling technology to reduce the noise coefficient and boost its voltage gain.The design principle of the circuit as well as noise coefficient are analyzed.Design simulation in SMIC 0.18 μm CMOS RF processis carried out S21 is more than 14 dB power gain and noise coefficient is less than 3 dB

with S11 and S22 less than-10 dB

while consuming 7.8 mW power under 1.8V supply

which meets the requirements of UWB communication system.