Modeling and analysis of the frequency dependence of class-E outphasing

Class E outphasing systems have been demonstrated to have high efficiency over a wide range of output power levels. This high efficiency is achieved through load modulation of class E branch PAs over their optimal load line. In this work, we extend the analysis of class E outphasing to describe its performance as frequency varies. The frequency variation in the optimal loading trajectories of conventional class E PAs are compared to that of the power combining network to show the effects of frequency variation on efficiency and output power. For the conventional class E outphasing system modeled here, the operating bandwidth is found to be 17.5% for a dynamic range variation of 1dB.