Design of Low Noise Amplifier using BFP 540 and BFP 640

Amplifiers play a critical role in a Communication System. They are used to increase the voltage, current, and/or power of a signal, in both transmitters and receivers. LNA is used at the front end of the receivers. Important properties of amplifiers include gain, input and output impedances measured using S-parameters, noise figure, stability, bias networks, interface with other circuits (ports). When designing a linear narrow band amplifier, the goal is to produce a design that is well-matched at the design frequency and has a good gain and low noise at that frequency. The S-parameters are a function of bias condition, so the result using a set of S-parameters are only valid at the bias conditions at which the S-parameters were measured or simulated. In this Paper, using bilateral approach, LNA is designed using RF transistor BFP 540 and BFP 640 (product of Infineon Technology). The BFP 540 gives considerable gain with minimum noise figure whereas, BFP 640 gives higher gain but at the cost of high noise figure.