Microwave power amplifiers fabricated from wide bandgap semiconductor transistors

The microwave performance of transistors fabricated from SiC and GaN-based semiconductors is described. It is demonstrated that these devices make possible microwave power amplifiers with superior RF power performance compared to devices fabricated from Si or GaAs. Room temperature RF output power on the order of 4 W/mm and 10-12 W/mm with near ideal power-added efficiency is available from 4H-SiC MESFET's and GaN-based HFET's, respectively. These devices are likely to find application in power amplifiers for base station transmitters for cellular telephone systems, HDTV transmitters, power modules for phased-array radars, and other applications. The devices are particularly attractive for applications that require high RF output power and operation at elevated temperature.