Trapping effects in wide-bandgap microwave FETs

It is well known that trapping effects can limit the output power performance of microwave field-effect transistors. This is particularly true for the wide-bandgap devices. In this paper, we review the various trapping phenomena observed in SiC and GaN-based FETs that contribute to compromised power performance. For both of these material systems, trapping effects associated with both the surface and with the layers underlying the active channel have been identified.