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 mu m and the 0.2- mu m gate is placed 0.5 mu m 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 mu m x 25 mu m 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 Wand associated PAE of 13-21% from low K-band to high Ka-band.