Better GaN circuits for radar and military systems

High-performance radiofrequency components and compound semiconductor technologies manufacturer RF Micro Devices has been awarded a $2.1 million contract from the Defense Advanced Research Projects Agency (DARPA) to enhance the thermal efficiency of gallium nitride (GaN) circuits used in high-power radar and other military systems.

The award is in association with the Near Junction Thermal Transport (NJTT) effort of DARPA’s Thermal Management Technologies (TMT) program. The goal of the DARPA NJTT initiative is to achieve a three-fold or greater improvement in power handling from GaN power amplifiers through improved thermal management of the near junction region. By combining thermally enhanced diamond substrates with RFMD’s GaN-on-SiC high power technology, RFMD expects to significantly improve power density and power handling capability.

Jeff Shealy, vice president and general manager of RFMD’s Power Broadband business unit, said, “RFMD is excited to work with DARPA to apply new technologies to our existing portfolio of GaN-based, high-power RF amplifier products. We expect the NJTT program will result in a new generation of higher performing, more compact RF high power amplifiers (HPAs) with lower operating temperature and greater RF power-per-unit area.”

RFMD’s partners in the program include the Georgia Institute of Technology, Stanford University, Group4 Labs and Boeing. Georgia Tech is recognised for its leadership in thermal testing, modelling and micro Raman thermography. Stanford University is the world leader in thermal measurement of the critical interface layers within a transistor die. Group4 Labs is a pioneer in the development of diamond substrates. Finally, Boeing plans to evaluate the resulting technology to assess its projected impact on future defence systems.

RFMD has been a leader in GaN technology since 2000 and has production released two high-power process technologies available through its open-foundry business model. RFMD’s GaN power devices have been deployed across multiple defence and commercial applications, including radar, milcom and CATV infrastructure. RFMD is the world leader in GaN-based CATV broadband amplifiers with superior linearity and output power and has shipped over 350,000 GaN-based CATV amplifiers into the commercial market.