GaN RF devices prove space-level reliability

April 13, 2016 // By Graham Prophet
Gallium nitride RF power transistors in Cree's Wolfspeed brand have been tested in a joint programme with high-reliability specialist KCB Solutions; the process upscreens the GaN RF HEMTs to Class S & Class K equivalent levels for aerospace users.

The transistors have completed testing to demonstrate compliance with NASA reliability standards for satellite and space systems. Wolfspeed’s GaN-on-SiC fabrication processes have, the company says, demonstrated reliability and performance, delivering more than 100 billion total hours of field operation with a FIT rate of less than-5-per billion device hours for discrete GaN RF transistors and multi-stage GaN MMICs.


Wolfspeed partnered with KCB Solutions, RF and microwave component specialist, to conduct a testing program to demonstrate that Wolfspeed’s GaN-on-SiC devices meet NASA EEE-INST-002 Level 1 reliability and performance standards, derived from the MIL-STD requirements for Class S and Class K qualifications.


“Our customers now have the ability to specify our GaN RF devices in the most critical aerospace, military, and satellite electronics systems,” said Jim Milligan, RF and microwave director, Wolfspeed. “Our proven GaN-on-SiC technology enables design engineers to make smaller, lighter, more efficient, and more reliable solid-state power amplifiers than are possible with conventional traveling wave tube (TWT) amplifiers or those designed with gallium arsenide (GaAs) devices."


“As an AS9100-certified facility with an extensive history of supplying Class S and Class K devices for aerospace and satellite electronic systems, KCB Solutions implemented a comprehensive testing program in conjunction with Wolfspeed to ensure that their GaN process was capable of producing devices that meet these demanding NASA standards,” said Ralph Nilsson, president, KCB Solutions. “This testing regime was derived from the established MIL-STD qualification requirements of Class S and Class K, and included evaluation for ESD, intrinsic reliability, SEM analysis, and radiation hardness.”


The testing program consisted of five test procedures conducted by KCB Solutions on Wolfspeed’s 25W GaN-on-SiC HEMT CGH40025F and their 25W 2-Stage X-Band GaN MMIC CMPA801B025F devices, which are produced using the company’s 0.4 µm G28V3 fabrication process. Both devices demonstrated no significant RF performance change after undergoing all the test procedures, including exposure to a cumulative dose of radiation exceeding 1Mrad.