Packaging and cooling of an X-band digital array radar T/R module

This paper describes the packaging and cooling design of a low-cost and compact X-band transmit/receive (T/R) module for a digital array radar, made by using both packaged and bare dies. Due to the high power generated by the Gallium-Nitride (GaN) dies and the dense environment, a liquid cooling system is required. The design and manufacturing of this cooling system is described together with thermal analysis. The dies are attached to the heat sinks using sintered nano-silver. The attachment procedure is described together with thermal expansion calculations.