Historical Aspect of Load-Modulated Balanced Amplifiers

This paper provides a comprehensive overview of the challenges and considerations associated with the design, implementation, and optimization of Load Modulated Balanced Amplifiers (LMBAs). Various research trends, all directed toward enhancing the benefits of the LMBA scheme and addressing its inherent limitations, are outlined. The initial focus is on maximizing efficiency and/or linearity, leveraging different techniques. Another noteworthy trend involves expanding the bandwidth of the LMBA architecture, a topic extensively covered in numerous papers. The other section delves into the most notable advancements in doherty power amplifier (DPA) and comparison with LMBAs. However, there’s still a need for new load-modulation power amplifier designs that can simultaneously maximize efficiency over extended power back-off and a broad frequency range. In essence, this review underscores the ongoing need for innovation in LMBAs design to meet the evolving requirements of 5G/6G communication systems.