RF Power: GaN Moves In for the Kill

Is gallium nitride (GaN) the wide bandgap material that will turn RF power generation on its head and relegate gallium arsenide (GaAs) and LDMOS (Laterally Diffused Metal Oxide Semiconductor) to the annals of history? Well you’d certainly think so, based on articles in the trade press, symposium papers, analyst reports, and corporate brochures. After all, GaN has at least ten times the power density per millimeter of transistor gate periphery, higher operating voltages (reducing impedance transformation issues), higher efficiency, and the ability to combine high RF power output over broad bandwidths at high frequencies. So is GaN, whether on substrates made of silicon, silicon carbide (SiC) or even diamond a slam dunk in every application?