Low Noise Amplifier Using Inductive Source Degeneration for Wideband Application

Abstract

This paper features a design of cascaded wideband low noise amplifier (LNA) operated from 4 – 7 GHz using inductive source degeneration with multi – section quarter wave transformer matching. This design implementing Super-low noise InGaAs HEMT MGF4937AM transistor which able to sustain until 20 GHz. Introducing inductive source degeneration will degrade the gain while improving the stability and maintaining the noise figure of the overall system. However, this problem can be eliminated by introducing cascaded topology which can increase the overall gain. Multi – section quarter wave transformer provides wideband characteristic and good input and output return loss on the desired frequency band. This LNA was designed based on FR4 microstrip characteristic and simulated using Advanced Design System (ADS) software. The LNA achieves input and output return loss of less than -10 dB, gain more than 15 dB and noise figure less than 0.5 dB respectively.