10W K band GaN MMIC amplifier embedded in Waveguide-based Metal Ceramic Package

This paper describes the design methodology and characterization of a 10W K Band packaged amplifier for space applications. The MMIC was developed on the new UMS $0.15 \mu\mathrm{m}$ gate length GaN technology on SiC substrate as the final stage of a downlink satellite transmitter in the 17.3-20.2 GHz frequency band. A dedicated hermetic package has been developed around the MMIC with an output waveguide transition (compatible of WR51) for low loss integration in a Solid State Power Amplifier (SSPA) output combiner. This packaged High Power Amplifier (HPA) measured in CW mode, reaches 10W output power in saturation, with an associated 35% of Power Added Efficiency (PAE) and 10° AM-PM variation. These data are provided for a package backside temperature of $90^{\circ}\mathrm{C}$.