Recent progress of high power GaN-HEMT for wireless application

In this paper, we describe the recent progress of high power GaN high electron mobility transistors (GaN HEMTs) for wireless base station application. First we introduce device technology and RF power performance of GaN HEMTs. Next, we discuss their reliability and cost issues which are great important for practical applications. As an example, GaN HEMTs on a low-cost conductive 3-inch SiC substrate are discussed. In addition, next generation wireless base station system will require extremely high efficiency power amplifiers when GaN HEMTs will be used at near saturation region. To suppress a forward gate leakage current at the saturation region, we developed a metal-insulator-semiconductor (MIS) gate GaN HEMT with an output power of over 100 W.