Investigation of the gate bias voltage influence on linearity performance of the ET and AET 10 W GaN HEMT PAs

This paper presents investigation on how linearity performance changes for different gate bias voltages for the ET and AET 10 W GaN HEMT power amplifier. It is shown that by selecting optimal gate bias voltage, AM-AM and AM-PM transfer characteristics can be more constant for a given power dynamic range which results with better linearity. Moreover, the efficiency can stay preserved. Benefit of selecting optimal bias point is possible simplification of the digital predistorter for ET PA linearization and achievement of maximal linearization capabilities out of AET PA.