Innovative Power Amplifier Gate Thermal Management for Active Radar Systems

This Phase-I SBIR MDA Proposal proposes the use of a new class of diamond-seeded solid-state material system for the manufacture of virtually all heat-generating solid-state electronics in X-band and Ballistic Missile Defense radar components and systems. In this proposal wherein much preliminary (MDA-funded) work has been demonstrated hitherto by the authors, Gallium Nitride-on-SiC power amplifiers in X-band radar are replaced with GaN-on-Diamond power amplifiers to enable nearly total and immediate heat extraction from the device’s active region. This proposal is specifically focused on exfoliating GaN FET epitaxy from SiC (rather than Si), and attaching the GaN FET to a CVD Diamond substrate. Free-standing polycrystalline CVD diamond – nature’s most efficient thermal conductor – enables nearly perfect heat extraction from a “hot” device, owing to the extreme thermal conductivity of diamond (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, 5+ W/mm of output RF power are expected to be measured from the GaN FET-on-Diamond device while operating at half the temperature of GaN-on-SiC devices. The semiconductor-on-diamond technology proposed here may be applied to Si, GaAs, GaN, SiC, SiGe, etc. at up to 8” in wafer diameter.