Low noise amplifier design and optimization

Low noise amplifiers are key components in the receiving end of nearly every communication system. These systems require very weak signals at the input. Primary purpose of LNA is to amplify the weak signal while keeping noise as little as possible. Performance of LNA is measured most notably by its gain and noise figure. There are also other performance criteria?s such as dynamic range, return loss and stability.At the beginning of project we aimed to design an amplifier for RF signal of satellite silicone tuners. After some observation we decided to design a LNA which works between 950 MHz to 2.1 GHz with required gain and noise figure. First of all, we selected the required active amplifier component. We chose NXP BFG 425 RF transistor for this purpose. We designed a biasing circuit which works as stable as possible regardless of temperature and other environment effects. We designed matching circuits for both input and output of this transistor. We draw PCB according to RF design requirements. After getting first measurements, we used AWR Microwave office for optimization of circuit to reach target design spec.