Analysis and design of a wideband and flat gain low noise amplifier

This thesis is concerned with designing and analyzing a broadband, ultra-low noise, flat gain low noise amplifier (LNA). The LNA uses the technology of pseudomorphic high electron mobility transistor (pHEMT) gallium arsenide (GaAs). It is specifically tuned for high-performance RF applications, including broadband communication systems, satellite communications, radar applications, and 5G. The design aims to simultaneously provide a low noise figure, uniform gain over a wide bandwidth, and excellent linearity. This thesis analyzes the effects of active and passive circuit elements used in the LNA design to obtain optimum performance characteristics besides sophisticated circuit modeling and simulation tools. The LNA is designed to exhibit a smooth gain profile over a wide frequency range, and the corresponding impedance-matching circuits are included accordingly. The noise figure is kept below 3 dB, and gain is limited to a tolerance of ±1.2 dB over the frequency range. These features enhance the device's effectiveness in demanding RF applications. The power consumption and thermal management performance of the device are evaluated. Measurements show that the designed LNA provides a low noise figure, stable gain, and substantial input/output isolation over a broadband spectrum. This designed LNA is expected to provide benefits such as a lower error rate, improved signal clarity, and extended application range in contemporary RF systems. This thesis provides both theoretical and practical contributions to the design of pHEMT GaAs-based LNAs and offers valuable insights for broadband RF applications.