RF GaN vs power-switching GaN

Power switching

Power GaN targets low R_DS(on), low gate charge, low output charge, high switching frequency, compact magnetics, and high efficiency. Main applications include USB-C chargers, server/data-center power, telecom rectifiers, solar microinverters, onboard chargers, 48 V automotive systems, class-D audio, drones, robotics, and solid-state protection.

Commercial high-voltage GaN is mostly 600/650 V lateral GaN-on-Si. The key system problems are dynamic R_ON, gate-drive margin, false turn-on, EMI, layout parasitics, short-circuit behavior, and thermal cycling.

RF and microwave GaN

RF GaN targets output power density, gain, power-added efficiency, linearity, high breakdown for voltage swing, and thermal stability. Main applications include 5G base stations, radar, satellite communications, electronic warfare, aerospace/defense PAs, and microwave/Ku/Ka-band amplifiers.

High-end RF GaN is usually GaN-on-SiC, often depletion-mode, with short gate lengths, field plates, SiN passivation, careful thermal design, and MMIC packaging. Trapping causes RF dispersion and memory effects; self-heating limits power density.

GaN vs SiC vs silicon

• GaN vs silicon: GaN switches faster with lower charge and higher power density, but is more sensitive to layout, gate drive, EMI, and dynamic behavior.
• GaN vs SiC: GaN is often strongest at 650 V and below with high frequency; SiC dominates 1200 V+, traction inverters, high-power modules, and rugged high-temperature environments.
• GaN vs IGBT: GaN eliminates tail current and enables much higher frequency; IGBTs remain cheap and robust for high-current lower-frequency industrial systems.