An S-Band GaN MMIC High Power Amplifier With 50 W Output Power and 55% Power Added Efficiency

This paper presents the experimental results of a monolithic microwave integrated circuit (MMIC) high power amplifier (HPA) in Gallium Nitride (GaN) technology conceived for S-Band active electronically scanned array systems. The MMIC is based on a three-stage architecture and it is realized on a commercially available 0.25 mu m GaN process. In order to maximize the efficiency and output power of the HPA, the harmonic terminations of the devices in the final stage were carefully optimized to actuate a class F working condition. Thanks to this, the MMIC is able to deliver an output power higher than 50 W with an associated gain and power added efficiency greater than 36 dB and 55%, respectively, in a fractional bandwidth larger than 13% within the S-Band. Even if the HPA comprises three stages, the overall chip area is limited to 6x5 mm(2).