Thermal Design of High Heat Dissipated Airborne Radars

The goal of thermal design of high beat dissipated solid state phased array radars for steady state conditions is to meet the following system requirements: (a) Maintain maximum systematic temperature variation over the array at less than 10 °C. This temperature gradient is required to achieve acceptable module-to-module electrical phase errors; (b) Maintain the device junction temperature within the module at less than 100 °C to achieve the specified system reliability. The detailed description of the system is presented. Because of a large heat dissipation (over 20 KW), the liquid-cooled approach is adopted for the design. A finite difference computer program developed in house was used to obtain thermal design and thermal tradeoff studies. Further, a full scale thermal test is performed to verify the results obtained from the analysis.