Ka-Band Power Amplifier Concepts in 22 nm CMOS FDSOI
Thesis event information
Date and time of the thesis defence
Topic of the dissertation
Ka-Band Power Amplifier Concepts in 22 nm CMOS FDSOI
Doctoral candidate
Master of Science Jere Rusanen
Faculty and unit
University of Oulu Graduate School, Faculty of Information Technology and Electrical Engineering, Circuits and Systems Research Unit
Subject of study
Electrical engineering
Opponent
Professor Patrick Reynaert, KU Leuven, Belgium
Custos
Docent Janne Aikio, University of Oulu
Advancing Power Amplifier Designs for More Efficient Millimeter Wave Telecommunications
As the world embraces 5G technology and prepares for the future of 6G, improving the efficiency of wireless communication is more important than ever. One major challenge lies in the design of power amplifiers (PAs), which are essential components in transmitters.
This research explores methods for improving the performance of integrated power amplifiers suitable for the millimeter-wave (mmWave) transmitter environment. mmWave transmitters often require hundreds of amplifiers to support large antenna arrays, leading to poor energy efficiency, heat issues, and high material costs. The traditional solution to ensure efficiency has been to use a highly nonlinear but efficient PA, which is then linearized using digital predistortion (DPD). However, this approach is becoming less feasible in mmWave phased arrays due to the sheer number of parallel PAs and the signal processing limitations of analog beamforming architecture.
This thesis focuses on finding innovative PA solutions using advanced complementary metal oxide semiconductor (CMOS) fully depleted silicon-on-insulator (FDSOI) technology, specifically in the 24–28 GHz frequency range, to address these challenges. One key finding was that by using back-gate biasing it was possible to reduce distortion in these amplifiers, allowing them to deliver more power while satisfying 5G linearity requirements.
Another important part of the research involved exploring and improving the design of balanced amplifiers. It was found that by biasing the amplifiers asymmetrically mismatches in the design could be compensated for, leading to better overall performance in terms of both efficiency and linearity. Additionally, a prototype design from the load-modulated balanced amplifier family was implemented, and measurements showed that the design offers good tunability and can improve both linearity and efficiency. These architectures provide a promising path forward for creating PAs that do not rely heavily on external correction techniques, such as digital predistortion, which are difficult to implement with mmWave transmitters.
In conclusion, the research paves the way for more efficient and linear PAs that can meet the needs of 5G and 6G networks, offering improved performance and lower energy consumption. The findings lay a foundation for future development in this area, which will be critical for the continued advancement of wireless communication technologies.
This research explores methods for improving the performance of integrated power amplifiers suitable for the millimeter-wave (mmWave) transmitter environment. mmWave transmitters often require hundreds of amplifiers to support large antenna arrays, leading to poor energy efficiency, heat issues, and high material costs. The traditional solution to ensure efficiency has been to use a highly nonlinear but efficient PA, which is then linearized using digital predistortion (DPD). However, this approach is becoming less feasible in mmWave phased arrays due to the sheer number of parallel PAs and the signal processing limitations of analog beamforming architecture.
This thesis focuses on finding innovative PA solutions using advanced complementary metal oxide semiconductor (CMOS) fully depleted silicon-on-insulator (FDSOI) technology, specifically in the 24–28 GHz frequency range, to address these challenges. One key finding was that by using back-gate biasing it was possible to reduce distortion in these amplifiers, allowing them to deliver more power while satisfying 5G linearity requirements.
Another important part of the research involved exploring and improving the design of balanced amplifiers. It was found that by biasing the amplifiers asymmetrically mismatches in the design could be compensated for, leading to better overall performance in terms of both efficiency and linearity. Additionally, a prototype design from the load-modulated balanced amplifier family was implemented, and measurements showed that the design offers good tunability and can improve both linearity and efficiency. These architectures provide a promising path forward for creating PAs that do not rely heavily on external correction techniques, such as digital predistortion, which are difficult to implement with mmWave transmitters.
In conclusion, the research paves the way for more efficient and linear PAs that can meet the needs of 5G and 6G networks, offering improved performance and lower energy consumption. The findings lay a foundation for future development in this area, which will be critical for the continued advancement of wireless communication technologies.
Last updated: 1.10.2024