A New Power Combining and Outphasing Modulation System for High-Efficiency Power Amplification

This paper describes a new power combining and outphasing system that provides both high efficiency and linear output control. Whereas conventional outphasing systems utilize two power amplifiers, the system introduced here combines power from four or more amplifiers. The proposed technique overcomes the loss and reactive loading problems of previous outphasing systems. It provides ideally lossless power combining, along with resistive loading of the individual power amplifiers over a very wide output power range. A conceptual development illustrating the operating principles of the system is provided, along with a representative design, detailed analysis, and supporting simulations. The relation of the proposed technique to multi-level resistance compression is also described. It is anticipated that the new power combining and outphasing modulation approach will find widespread use in applications where both high linearity and high efficiency are desired.