S-Band Low-noise Transistor Amplifier

Abstract

This article describes an S-band transistor amplifier for the microwave communication system which has been designed and developed to have both low noise figure and large dynamic range. The amplifier provides a minimum gain of 20dB and noise figure of 4.8dB (max) in the required 20% bandwidth at S-band. The output power for 1dB gain compression is +3 dBm.The amplifier consists of three stages. The first low noise stage using NEC V578 transistor is biased at low current levels for best noise performance. The second and third stage using NEC 2N5761 transistors are biased at higher current levels for increased saturation level.