S3-P3: Advanced no-field-plate AlGaN/GaN hemts for millimeter-wave MMIC applications

We report successful development of an advanced no-field-plate AlGaN/GaN high electron mobility transistors (HEMTs) for millimeter-wave (MMW) applications. The HEMT adopts a reduced source-drain spacing of 2 μm and the 0.2-μm gate is placed 0.5 μm off the source electrode. Additionally, the devices and monolithic microwave integrated circuits (MMICs) are fabricated on the SiC substrate of 2mil, enabling the fabrication of 15 μm × 25 μm slot via holes for realizing low inductance and more compact devices to facilitate MMW MMIC design. As a result, the narrow band MMICs have achieved an output power of 10.4 W with associated power added efficiency (PAE) of 31% at 28 GHz, and 10.7W and 27% at 36 GHz, respectively. Besides, a state-of-the-art 2-stage single-ended wideband MMIC demonstrates output power of 5–7.9 W and associated PAE of 13–21% from low K-band to high Ka-band.