Design Of C-band Low Noise Amplifier

As one of microwave receiving system modules,Low Noise Amplifier plays a decisive role on the entire system receiving sensitivity and noise performance. The high electronic mobility transistor is a Field Effect Transistor, which has a series of merits, such as high-frequency, low noise, high efficiency, and so on. Multistage low noise amplifiers with HEMT are widely used in satellite receiving systems, electronic systems and radar systems.C-band low noise amplifier (LNA) circuit has been designed in this thesis based on analyzing the principles of microwave low noise amplifier. The circuit is made up of three stages with ATF-36077. Matching circuits of Bias circuit, input stage, middle stage and output stage have been implemented through simulation analysis. Feedback microstrips are added to source electrode to improve stability of the circuit,negative feedback network is added to the transistor between gate and source in the third stage to improve the circuit's gain flatness and input-output VSWR. The whole circuit is simulated and optimized by ADS. Simulation results show that LNA in 3.7GHz-4.2GHz band, the gain greater than 30dB, noise figure less than 0.6dB, VSWR less than 2. The result shows that it achieves the requirement of design objective.