Innovative Two-Phase Heat Spreader For X-Band T/R Modules

We propose to develop a T/R module housing that incorporates two-phase thin-film evaporators adjacent to each T/R module in order to increase greatly the lateral spreading within the housing. Our unique thin-film evaporators remove large amounts of heatvia ultra thin-film evaporation of a working fluid. After evaporation, the fluid's vapors pass through a semi-permeable membrane and condense on a surface in contact with the T/R module board. The lower thermal resistance of our T/R module housing willreduce the operating temperatures of future higher-power MMIC's, which will increase the reliability of the radar system.Our proposed design has many advantages. The cooling mechanism is ideal for the limited space available inside a T/R module housing. The thin-film evaporators will be able to remove heat at rates of up to 200 W/cm2, which is comparable to spray coolingmethods but with lower power and space requirements and fewer ancillary components. Our thin-film evaporators incorporated into the T/R module housing will reduce the thermal gradient across the housing and allow the operation of the radar system at highpower densities and frequencies. Similar active cooling packaging systems could be designed for other high-heat flux electronic devices, such as solid-state lasers, electronic power modules, computer network servers, and computer workstations withmultiple processors. ATEC is currently working on developing a potentially high volume electronic cooling product utilizing our thin-film evaporator technology.