Manufacturing

Many military radio frequency (RF) systems, like radar and communication systems, use a class of power amplifiers (PAs) called monolithic microwave integrated circuits (MIMIC). MMIC PAs using gallium nitride (GaN) transistors hold great promise for enhanced RF performance, but operational characteristics are strongly affected by thermal resistance. Much of this resistance comes at the thermal junction where the substrate material of the circuit connects to the GaN transistor. If the junction and substrate have poor thermal properties, temperature will rise and performance will decrease.

Significant enhancements in fundamental device materials, technologies and system integration have led to rapid increases in the total power consumption of DoD systems. In many cases, power consumption has increased while system size has decreased, leading to an even greater problem with heat density. Thermal management of DoD systems often imposes the main obstacle to further enhancements.