Low Noise and Low Distortion Performances of an AlGaN/GaN HFET

Yoshito IKEDA
Motonori ISHII
Tomohiro MURATA
Tsuyoshi TANAKA
Takashi EGAWA
Takashi JIMBO

IEICE TRANSACTIONS on Electronics   Vol.E86-C    No.10    pp.2058-2064
Publication Date: 2003/10/01
Online ISSN: 
Print ISSN: 0916-8516
Type of Manuscript: Special Section PAPER (Special Issue on Heterostructure Microelectronics with TWHM2003)
AlGaN/GaN HFET,  low noise amplifier,  noise figure (NF),  intermodulation distortion,  

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We present ultra low noise- and wide dynamic range performances of an AlGaN/GaN heterostructure FET (HFET). An HFET fabricated on a high quality epitaxial layers grown on a semi-insulating SiC substrate exhibited impressively low minimum noise figure (NF min ) of 0.4 dB with 16 dB associated gain at 2 GHz. The low NF (near NF min ) operation was possible in a wide drain bias voltage range, i.e. from 3 V to 15 V. At the same time, the device showed low distortion character as indicated by the high third order input intercept point (IIP3), +13 dBm. The excellent characteristics are attributed to three major factors: (1) high quality epitaxial layers that realized a high transconductance and very low buffer leakage current; (2) excellent device isolation made by selective thermal oxidation; (3) ultra low gate leakage current realized by Pd based gate. The results demonstrate that the AlGaN/GaN HFET is a strong candidate for front-end LNAs in various mobile communication systems where both the low noise and the wide dynamic range are required.