RF Chip Design Using GaN for High-Power Applications

Abstract: The growing demands of modern communications, radar, and satellite systems require power amplifiers that deliver high output power, high efficiency, and compact form factor. Wide-bandgap Gallium Nitride (GaN) high-electron-mobility transistors (HEMTs) have become the preferred technology for high-power RF and microwave applications due to their high breakdown voltage, high electron saturation velocity, and strong thermal robustness. This paper presents a comprehensive design methodology and simulation validation for a GaN-based Class-E high-power RF amplifier targeted at sub-1 GHz and S-band operation. The design flow includes device selection, large-signal behavioral modeling, harmonic-balance simulation, impedance matching, thermal considerations, and layout recommendations. Simulated results demonstrate output power above 12 W, small-signal gain ≈28 dB, and Power-Added Efficiency (PAE) exceeding 80% under idealized conditions; the paper also compares these results with recent published GaN PA developments and discusses reliability and manufacturability considerations for tape-out and prototyping. Recent experimental and review literature is cited to contextualize design choices and highlight gaps for further work.

Keywords: Gallium Nitride (GaN), HEMT, RF power amplifier, Class-E, Power-Added Efficiency (PAE), MMIC, thermal management.