High Performance AlN/GaN/AlN/GaN Double Channel Fin-HEMT for Ka-band Low Voltage Wireless Communication Applications

In this letter, a high performance AlN/GaN/AlN/GaN double channel Fin-HEMT (DCF-HEMT) is proposed for Ka-band low voltage mobile communica-tion applications. Attributed to Fin-structure, the fabricated DCF-HEMT demonstrated improved off-state gate control characteristics. With a low sheet resistance (<italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">R</i><sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">SH</sub>) of 174 Ω/□ and the short source-drain spacing of 1.5 μm, the AlN/GaN/AlN/GaN DCF-HEMT delivered a high maximum current density of 2613 mA/mm. The off-state electric field was dispersed by double-channel structure, resulting in a low current collapse of about 7.5%. The load-pull meas-urements were carried out at 28 GHz and low operating voltages. The proposed DCF-HEMT delivered a peak pow-er-added efficiency (PAE) of 56.83% at 6 V and 61.55% at 10 V, when matched for maximum PAE. It also achieved a saturated power density (<italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">P</i><sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">SAT</sub>) of 3.13 W/mm at 6 V and 5.31 W/mm at 10 V, when matched for maximum <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">P</i><sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">OUT</sub>. Moreover, an OIP<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> of 34.07 dBm highlights the excellent linearity performance of the AlN/GaN/AlN/GaN DCF-HEMT. The ex-cellent results reveal the great potential of AlN/GaN/AlN/GaN DCF-HEMT in low voltage wireless communication applications at Ka-band.