Systems houses and research labs from seven European nations are working together on GaN HEMT technology for critical defense applications.
Defense radar and communication systems as well as wireless communication systems have a drastic need for increased RF performance and high-power, high-efficiency, high-linearity and low-cost monolithic amplifiers operating in the 1–40 GHz frequency range.
As mainstream III-V technologies fall short when trying to address all of these needs simultaneously, GaN HEMT technology has emerged as an attractive option. Recognizing that the Europe Union’s defense industries need a supply chain and GaN HEMT capability, a €40 million EUROPA research initiative called KORRIGAN — for Key Organization for Research on Integrated Circuits in GaN—is currently underway.
The seven nations contributing to the KORRIGAN consortium include France, Italy, The Netherlands, Germany, Spain, Sweden and the United Kingdom. A key goal is to establish a stand-alone European supply chain and foundry service.
The 29 corporate, university and lab partners, lead by Thales Airborne Systems, are researching materials, circuit design, modeling, processing, reliability evaluation, thermal management and packaging. The benefits of GaN technology will finally be evaluated at the system level for critical defense applications up to 20 GHz with the fabrication and test of circuit, MMIC and module demonstrators.
Several demonstrators will be designed to validate GaN technology for various applications: S-band HPA, X-band and wideband HPA, LNA and switches.
The superior inherent material properties of the newer wide band-gap materials such as GaN, GaAlN and InGaN include:
• high breakdown electric field,
• high electron mobility and saturation carrier velocity,
• and high thermal conductivity.
The higher breakdown electric field allows operation at higher voltages, which means that for the same power level, much higher matching impedances, lower power recombination losses in multi-transistor amplifiers and better energy efficiencies at lower circuit complexity will be possible.
The intrinsic high thermal stability of the material should allow operation at higher temperatures, requiring less stringent (and less expensive) thermal management solutions for the packaging of high power amplifiers.
GaN power HEMTs should ultimately show very high reliability. Due to the very high power-density of GaN devices, however, there is a real need to evaluate the technology reliability and to explore packaging and heat sink solutions, which will provide optimum thermal management.
The KORRIGAN project will address research issues and enable the development of leading GaN technology on the horizon for 2009.