Developing GaN HEMTs for high efficiency

An efficiency of AlGaN/GaN High Electron Mobility Transistors (HEMTs) were improved for Ku band. The AlGaN/GaN HEMTs were developed with an achievable fmax of 138 GHz, which depended on the thickness of the AlGaN barrier layer and the gate length. A 6.4 mm gate periphery device was thereafter designed with matching circuits on an alumina substrate on a metal carrier plate. The output power achieved 20 W at 26 GHz.