Innovative Thermal Management Solutions for Radar T/R Modules

This Phase-I STTR proposes the use of a new class of diamond-seeded solid-state material system for the manufacture of intense heat-generating solid-state electronics in Ka-band Ballistic Missile Defense radar components and systems. In this proposal wherein much preliminary work (also MDA-funded) has been demonstrated hitherto by the authors, Gallium Nitride-on-SiC power amplifiers in Ka-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 Phase-I is focused on producing a 1-10 Watt (or 10kW in Phase-II) Ka-band (34-36GHz) GaN-on-Diamond Power Amplifier module. Polycrystalline free standing 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 35-, 150- and 390-W/m/K respectively; diamond is 1200-2000 W/m/K per 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 GaAs, GaN, SiC etc. at up to 8” in wafer diameter.