Low noise amplifiers (LNAs) play a key role in radio receiver performance. A LNA is an electronic amplifier that amplifies a very low power signal without significantly degrading its signal-to-noise ratio. An amplifier will increase the power of both signal and the noise present at is input. Low noise amplifiers are designed to minimize the additional noise. Designers minimize the additional noise by considering trade-offs that include impedance matching, choosing the amplifier technology and selecting biasing conditions. Performance of different design is compared with respective noise figure, gain, input and output reflection coefficient. Advanced design system (ADS) tool was used for design and simulation of LNA.

Design of 2.4 GHz Low Noise Amplifiers for Wireless Communication System

Abstract This thesis work was performed at RUAG Space AB, Goteborg, Sweden. The aim of this thesis is to test the performance boundaries of SiGe based heterojunction bipolar transistor in designing a low noise amplifier meant for GNSS applications. After careful consideration of different alternatives for active components in SiGe HBT process, BFY640-04 from Infineon was selected as the active component for the design. Later, different topologies have been evaluated in Advanced Design System (ADS) software and finally a common emitter topology is selected considering cost-effectiveness, performance and simplicity. Apart from this, the functionality of a limiter component namely, GG-77015-01 from Microsemi has been tested by placing it in front of the LNA. The purpose of this is to know if it can prevent the LNA from high power levels and to study its overall effect on noise figure, gain and linearity. The prototypes were fabricated on a hardback PCB consisting of Roger Duroid 6002 substrate. The designed LNA has less than 1 dB (excluding limiter) noise figure, gain of 17-13 dB and input return loss of 6 dB. It is powered by a single positive supply of +5 V and has very low DC power consumption of 15 mW. Also, the noise figure is fairly low in the entire L-band apart from current GNSS bands, which provides possibility of this design to be useful in future GNSS applications too. (Less)

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Robert Petersson

Papers

Design and Test of an L-Band (GNSS) Low Noise Amplifier and Limiter