Master's thesis presentation Jamal Ur Rasool Haider

Main Supervisor: Dr. Rui Hou, Ericsson
Co-supervisor: Dr Paul Saad, Ericsson/Han Zhou, Chalmers

Abstract: In the current era characterized by rapid advancements in wireless communication, the demand for high data rates and low power consumption in various communication networks, including mobile base stations, poses significant challenges. To address these challenges, it is imperative to explore and devise new power amplifier solutions that offer substantial data rates with multi-band capability and improved energy efficiency. This thesis presents a comprehensive solution in the form of a Dual-Band Doherty Power Amplifier (DB-DPA) to meet these pressing requirements. DPAs have gained considerable popularity due to their ability to achieve high back-off efficiency across a wide range of output power levels. The primary objective of this research is to design and simulate a symmetrical DB-DPA using state-of-the-art GaN-HEMT technology for the frequency bands of 1.85 and 2.65 GHz. The load modulation network comprises a wideband combiner followed by a 4-sections Chebyshev transformer. Subsequently, the designed DPA is fabricated, measured, and the obtained results are presented and analyzed.

Through extensive simulations and measurements, this study demonstrates that the proposed DB-DPA design delivers satisfactory performance in terms of efficiency and gain for both the lower and upper-frequency bands of 1.85/2.65 GHz. At a peak power of 47.9/47.3 dBm, the DB-DPA achieves a drain efficiency of 55.6/54.5%. Furthermore, at a 6 dB back-off level, the DB-DPA exhibits an efficiency of 41.2/44.6% and a gain of 19.5/15 dB for the desired frequencies. These characteristics position this design as a promising candidate for communication applications. The findings presented in this research emphasize the potential of the proposed DB-DPA design and provide a viable solution that meets the growing requirements of the wireless industry. The comprehensive investigation conducted through simulations and measurements contributes to the body of knowledge in the field and provides valuable insights for further advancements in power amplifier design.