20W S-band high power amplifier using stacked FET topology

Power amplifiers based on stacked Field Effect Transistor (FET) stages are often applied in silicon based technologies. The application of stacked FETs in Gallium Arsenide (GaAs) power amplifiers potentially leads to Monolithic Microwave Integrated Circuits (MMIC) devices with increased output power per chip area due to the efficient power combining. Furthermore the increased supply voltage results in lower supply currents. In this paper the design and results of a 20 W S-band High Power Amplifier (HPA) are given. Stability and thermal aspect are addressed and the experimental results show an output power in excess of 20 W with a peak Power Added Efficiency (PAE) of more than 40 %.