Microwave Journal
www.microwavejournal.com/articles/25383-wolfspeed-gan-hpas-have-247365-reliability-confirmed-by-lockheed-martin

Wolfspeed GaN HPAs have 24/7/365 reliability confirmed by Lockheed Martin

October 29, 2015

Wolfspeed, a Cree Company and a leading global supplier of GaN-on-SiC high electron mobility transistors (HEMTs) and monolithic microwave integrated circuits (MMICs) with best-in-class reliability, has partnered with Lockheed Martin to provide GaN high power amplifiers (HPAs) for the U.S. Air Force’s Space Fence, which will significantly improve the timeliness with which operators can detect space events that could potentially threaten GPS satellites or the International Space Station.

Scheduled to go online from Kwajalein Atoll in the Marshall Islands in 2018, Space Fence will accurately track the estimated 500,000 objects — such as spent rocket boosters, stray hardware, and other debris — that are floating in the same space as the satellites that so much modern technology depends on. Developed by Lockheed Martin in partnership with Space Military Command and the U.S. Air Force Life Cycle Management Center/Space Command Control and Surveillance Division, Space Fence incorporates a scalable, solid-state S-Band radar with a high wavelength frequency that is capable of detecting much smaller objects than the current system, and will thus improve accuracy, quicken response time, and expand surveillance coverage.

Having completed the critical design review and begun construction, Lockheed Martin’s Space Fence team is currently focused on the production of technology that will bring the system online, and has recently reached a major design milestone by confirming the long-term reliability of Wolfspeed’s GaN HPA technology, which is integral to meeting the project’s efficiency and availability requirements and will allow Space Fence to track 10 times more space junk than the current system. After more than 5,000 hours (or nearly seven months) of accelerated stress testing, Lockheed Martin has demonstrated greater than 99 percent  confidence that Wolfspeed’s GaN HPAs will meet the long-term reliability goals for the Space Fence program.

“These test results represent the culmination of more than a decade of shared investment in GaN technology,” said Steve Bruce, vice president, Advanced Systems at Lockheed Martin Mission Systems and Training. “GaN HPAs provide significant advantages for active phased array radar systems like Space Fence, including higher power density, greater efficiency, and improved reliability over previous technologies.”

“Wolfspeed is extremely pleased to work with Lockheed Martin and provide GaN MMIC HPA technology in support of the Space Fence program,” said Jim Milligan, RF and microwave director, Wolfspeed. “Our high performance commercial GaN products have been fielded for many years in a variety of military and commercial applications, and the successful completion of this most recent reliability milestone further validates that GaN technology has matured enough to support the mission critical 24/7/365 coverage required by the Space Fence system.”

In addition, Wolfspeed also offers a variety of catalogue S-Band GaN radar devices, such as the CMPA2735075F, which is a two-stage GaN HEMT high power MMIC amplifier that provides saturated RF output power of 75W over 2.7–3.5GHz with power gain of 20dB in a small package (0.5” x 0.5”), and was the first S-Band GaN HEMT MMIC on the market to offer 60% typical PAE with RF pulse widths of 300µs and a 20% duty cycle.

For more information about Lockheed Martin’s Space Fence, please visit www.lockheedmartin.com/us/products/space-fence.html. For more information about Wolfspeed’s catalogue S-Band GaN radar devices, please visit wolfspeed.com/RF/Applications/RF-Applications/Radar. For all other inquiries about Wolfspeed™ RF components and foundry services, please visit wolfspeed.com/RF or contact Sarah Miller, marketing, Wolfspeed, at sarah.miller@wolfspeed.com or 919-407-5302.