A measurement set-up and methodology combining dynamic biasing and baseband predistorsion for high efficiency and linear amplifier design

This paper presents a time domain envelope measurement system that enables the study and the optimization of high efficiency and linear power amplifiers by applying both envelope tracking and digital base band predistorsion techniques. A man focus of this paper is the description of the set up architecture along with its capability to achieve in depth investigations on the dynamic behavior of envelope tracking amplifiers (ET PAs). To reach optimal efficiency and linearity performances ET PAs need to be accurately characterized under dynamic operating conditions in order to perform a well suited control of RF input envelope and Was voltage tracking signals. The proposed set up is applied here to a 10 W GaN Power amplifier from Cree at 3.6 GHz.