Design and Implementation of an Encapsulated GaN X-Band Power Amplifier Family

This paper describes the design and verification results of two wideband class AB High Power Amplifiers (PA), encapsulated in commercial packages. Both amplifiers designed on WIN Semiconductors' 0.25 $\mu$ m GaN on SiC technology. The selected GaN process features compact common-source (CS) transistor layouts with individual source grounding vias. The family spans the whole X-band frequency with the first design tuned between 7–11 GHz and the second design tuned between 10–12 GHz. Both designs have saturated power output greater than 25 W throughout the whole bandwidth with peak power added efficiency at 30%. A multistage power combining matching strategy to achieve a tradeoff in wideband performance and power output is given. In depth discussion of the MMIC design of the PAs is supported by a discussion of the thermal management of the packages, including the PCB design and active cooling methodology, in order to present a fully functional PA family.