AlGaN/GaN High Electron-mobility Varactors on Silicon Substrate

This paper gives a first presentation of an AlGaN/GaN high electron-mobility varactor grown on a high resistivity silicon substrate. The technology is compared to a GaN on silicon carbide technology and the devices are characterized by fitting a large-signal model. Compared to GaN on SiC varactors a similar performance is achieved. Only slightly increased losses due to higher sheet and contact resistance lower the Q-factor of the GaN on Si varactor.