Investigation of the practical output load impedance sensitivity of a 10 W GaN device subject to gate bias variation

Abstract

This paper shows practical output load impedance sensitivity of a 10 W GaN HEMT device depending on a gate bias. In order to determine how much the output impedance changes for different biasing points, Load Pull measurement is performed for different biasing points from deep class-AB to class-A. It has been found that load impedances for simultaneously high output power as well as high power added efficiency (PAE) do not change much. It is also shown that matching impedances for second and third harmonic, optimized for PAE have a common overlapping area. These results indicate that this device is suitable for dynamic gate biasing.