Gallium nitride (GaN) continues to reach new milestones as a leading semiconductor technology. As a replacement for silicon carbide (SiC) on diamond, for instance, Raytheon’s GaN-on-diamond devices reportedly boasted three to five times’ higher thermal conductivity in a recent demonstration. As a result, the technology could enable next-generation radar, communications, and electronic-warfare systems to perform at higher levels while reducing cost and size.

The demonstration used a 10-x-125-μm (1.25-mm) GaN-on-diamond high-electron mobility transistor (HEMT). The device represented a unit cell for constructing power-amplifier (PA) monolithic microwave integrated circuits (MMICs). Those MMICs serve as the foundation for solid-state RF transmitters and active electronically scanned arrays. With the GaN-on-diamond technology reducing thermal resistance within the device, they can be used at higher power densities. This aspect helps to reduce the cost, size, weight, and power of these systems.

These results build upon the company’s first demonstration of GaN-on-diamond transistors in 2009 and GaN-on-diamond MMICs in 2011. Raytheon’s diamond material is synthesized using a chemical-vapor-deposition (CVD) process that allows for higher conductivity. That process and technology are an integral part of Raytheon’s radar programs including Air and Missile Defense Radar and Next Generation Jammer.