Evolution of the Nonuniform Distributed Power Amplifier: A Distinguished Microwave Lecture

The emergence of gallium nitride (GaN) monolithic microwave integrated circuit (MMIC) technology has been a real game-changer for high-power amplifier and control components. When compared with the incumbent gallium arsenide (GaAs) MMIC technology, a near order of magnitude increase in output power and power handling was achieved with similar efficiency, noise, and frequency capability. In addition, GaN transistors epitaxially grow on high-thermal conductivity substrates such as silicon or silicon carbide (SiC), helping to mitigate some thermal issues associated with highoutput power density.