Innovative Power Amplifier Gate Thermal Management for Active Radar Systems

This Phase-II SBIR Navy proposal proposes the use of a revolutionary new class of semiconductor materials (Gallium Nitride-on-Diamond) in the manufacture of solid-state 100-Watts, 50-60% efficient MMIC power amplifiers in X-band radars. Polycrystalline free standing CVD diamond – close to nature’s most efficient thermal conductor – enables nearly perfect heat extraction when the diamond is brought to within a few tens of nanometers of the “hot” junction. For reference, GaAs, Si, and SiC are 35W/m/K, 150W/m/K and 390W/m/K respectively; diamond ranges from 1200-2000 W/m/K depending on quality. In the proposed scheme, the device’s active epitaxial layers are removed from their original host substrate and transferred to a specially treated low-cost CVD diamond substrate using a proprietary low-cost manufacturable scheme. The semiconductor-on-diamond technology proposed here may be applied to Si, GaAs, GaN, SiC, SiGe, etc. at up to 8” in wafer diameter. Notwithstanding prior GaN-on-Diamond work, this will be the first GaN-on-Diamond MMIC ever demonstrated.