Drawing on internal and government R&D funds Raytheon has been a pioneer of gallium nitride (GaN) semiconductor technology, with its own foundry to produce durable, military-grade transmit/receive modules (TRMs) for active electronically scanned array radars. The technology is already employed in the company’s SPY-6(V) air and missile defense radar that is being developed for U.S. Navy vessels, and in the next-generation jammer for EA-18G Growler electronic warfare aircraft, and now it is considered as production-ready as part of the ongoing modernization effort for the Patriot air defense system.
GaN is revolutionizing the radar world. Compared with radars based on gallium arsenide (GaAs) semi-conductors the technology allows arrays to provide more capability and range, while consuming less energy. It also offers lower life-cycle costs than GaAs radars by allowing the removal of several “readiness drivers,” or elements in the radar’s critical path of processes that have exhibited higher failure rates, in turn reducing maintenance requirements and increasing mean time between failures.
Using company funds and identifying a desire by many of the 16 Patriot customers to adopt the technology at some point, Raytheon has adapted its GaN technology to the Patriot application, and has already amassed around 3,000 hours of trials time with Patriot GaN arrays.
Many customers also have a desire to move away from a sector-based air defense to a 360-degree coverage. Raytheon has already demonstrated a 360-degree capability by linking separate GaN arrays, demonstrating the seamless hand-off of targets from one to another, and is now in the process of building an integrated 360-degree radar, which will enter test soon. While this is considered to be the “full spec” GaN product, the company recognizes that some customers might prefer to retain a sector-based capability with a staring array, which remains of considerable relevance in the air defense segment.
At present, there is no clearly defined timeline for the fielding of a 360-degree GaN radar for Patriot, but it is an important element in the long-term modernization plan for the international user group, which plays a major part in driving and funding Patriot developments. However, new user Poland has outlined a desire to have a 360-degree GaN radar in around four years.