Advance Thermal Management of Large Multiband Phased Arrays

The main issue preventing widespread use of x-band antennae systems throughout various military platforms is cost. Cheaper assembly processes, such as automated pick and place, are needed to produce antennas using wideband gap semiconductor materials such as GaN and SiC. Higher power and frequency pose challenges to the thermal design of the array. Advanced heat sinks are needed which are lightweight, CTE matched to GaN/SiC, highly thermally conductive, available in large sizes (22" x 22" x 1") in production quantities, and producible at low cost. Currently, the heat sink material with these collective attributes is aluminum graphite composites. Al/Gr heat sinks could be a technology enabler when it comes to manufacturability and producibility for future phased arrays. Though Al/Gr has merit for this application, several technical issues must be addressed to determine final applicability for use in large multi band phased arrays: corrosion resistance, soldering adaptability, and mechanical strength. Raytheon is currently developing large multi band phased arrays with emphasis on Al/Gr composite base plates. The basis of this program is to help MMCC develop Al/Gr technology to support Raytheon's multi band phased array. The emphasis of Phase I will entail corrosion prevention, structural suitability, and solder joint integrity.