Abstract: This paper introduces the application of ADS software to design the design of a UHF/SHF monolithic low noise amplifier, expounds the devices in the microwave monolithic design choice, in the frequency range of 2.65~3.45 GHz, the noise figure is less than 1.4 dB, the gain is larger than 25 dB, the flatness is 0.5 dB, voltage is less than 1.5 in Bobbi. The results show that the performance of low noise amplifier, low cost, small volume, high rate of finished products, can meet the requirements of modern equipment.