Yihenew Wondie (PhD)Gamachu Tafari2025-04-252025-04-252025-03https://etd.aau.edu.et/handle/123456789/5361Class AB, Doherty, and Envelope Tracking Power Amplifiers (ETPA) are the three types of power amplifiers that are thoroughly compared in this thesis in the context of 5G networks. Current communication standards require power amplifiers to achieve high efficiency over increasingly larger dynamic ranges and bandwidths while maintaining strict linearity criteria. The study uses key criteria like power-added efficiency, linearity, gain, and output power to evaluate their performance. Simulations were conducted using MATLAB and the Advanced Design System to evaluate amplifier properties under various settings, including the use of Digital Pre-Distortion to improve nonlinearity. The results showed that Class AB amplifiers achieved PAE of 51.090 % and improved AMAM Conversion. Excellent back-off efficiency and significant advantages in high-power scenarios are exhibited by Doherty amplifiers, especially when DPD integration is employed for enhanced linearity. Despite achieving 70% PAE and demonstrating superior efficiency over a broad dynamic range, envelope tracking amplifiers require complex design due to their reliance on dynamic voltage control. By balancing the trade-offs between linearity and efficiency, this study determines the optimal amplifier topologies for 5G networks that are both high-performance and energy-efficient. These discoveries contribute to the advancement of the technology by revealing the future applications of power amplifiers in wireless communication systems.en-USEnvelope Tracking PADoherty PAFifth generationefficiencyGainlinearityOutput PowerDigital Pre-Distortionmassive MIMOPower AmplifiersThesis