Fujitsu Limited and Fujitsu Laboratories Ltd. have developed a crystal structure that both increases current and voltage in gallium-nitride (GaN) high electron mobility transistors (HEMTs). The structure effectively triples the output power of transistors used for transmitters in the microwave band.
The crystal structure improves operating voltage by dispersing the applied voltage to the transistor, and thereby prevents crystal damage (patent pending). This technology enabled GaN devices to achieve what is thought to be the world's highest power density at 19.9 W/mm of gate width for a GaN HEMT employing an indium-aluminum-gallium nitride (InAlGaN) barrier layer.
The GaN HEMT technology can serve as a power amplifier for equipment in weather radar applications. Applying the developed technology to this area, it is expected that the observation range of the radar will be expanded by 2.3 times, enabling early detection of cumulonimbus clouds that can develop into torrential rainstorms.
Fujitsu and Fujitsu Laboratories will conduct an evaluation of the heat resistance and output performance of GaN HEMT power amplifiers using this technology, with the goal of commercializing high output power, high frequency GaN HEMT power amplifiers for use in applications such as radar systems, including weather radar, and 5G wireless communication systems by fiscal 2020.