Fujitsu has been developing gallium nitride high electron mobility transistors (GaNHEMT) for small transmitter amplifiers for Long Term Evolution (LTE) base stations. The use of GaN-HEMT in highly efficient transmitter amplifiers has attracted much attention because of its high breakdown voltage characteristics. High-efficiency amplifiers with high gain are needed to decrease the power consumpt...

2010 marked the 30 anniversary of the HighElectron Mobility Transistor (HEMT). The HEMT represented a triumph for the, at the time, relatively new concept of bandgap engineering and nascent molecular beam epitaxy technology. The HEMT showcased the outstanding electron transport characteristics of twodimensional electron gas (2DEG) systems in III-V compound semiconductors. In the last 30 years, ...

This paper presents a new architecture for an AlGaN/GaN HEMT frequency doubler using the active integrated antenna design approach. A microstrip patch antenna designed at the second harmonic is integrated with the HEMT. The antenna operates as a fundamental frequency reflector in this circuit. Using AlGaN/GaN with 1mm gate periphery, a 4 8 GHz frequency doubler was designed by the suggested des...

In the photosynthetic bacterium Rhodobacter sphaeroides, two genes, hemA and hemT, each encode a distinct 5-aminolevulinic acid (ALA) synthase isozyme (E. L. Neidle and S. Kaplan, J. Bacteriol. 175:2292-2303, 1993). This enzyme catalyzes the first and rate-limiting step in a branched pathway for tetrapyrrole formation, leading to the biosynthesis of hemes, bacteriochlorophylls, and corrinoids. ...

In the present work, Dual Material Gate (DMG) AlGaN/GaN High Electron Mobility Transistor (HEMT) has been studied for its improved linearity performance on the basis of VIP3 (i.e. extrapolated input voltage at which the first and third order harmonic voltages are equal) and compared with the conventional Single Material Gate (SMG) AlGaN/GaN HEMT. The influence of the device parameters such as t...

In this work, a high temperature THz detector based on a GaN high electron mobility transistor (HEMT) with nano antenna structures was fabricated and demonstrated to be able to work up to 200 °C. The THz responsivity and noise equivalent power (NEP) of the device were characterized at 0.14 THz radiation over a wide temperature range from room temperature to 200 °C. A high responsivity Rv of 15....

We report improved sensitivity to NO, NO₂ and NH₃ gas with specially-designed AlGaN/GaN high electron mobility transistors (HEMT) that are suitable for operation in the harsh environment of diesel exhaust systems. The gate of the HEMT device is functionalized using a Pt catalyst for gas detection. We found that the performance of the sensors is enhanced at a temperature of 600 °C, and the measu...

In this paper AlGaN/GaN heterostructure device analysis carried out which are capable for high power and frequency with performances far superior to those offered by the mainstream silicon technology and other advanced semiconductor technologies. AlGaN/GaN HEMT primarily driven by microwave wireless communication applications need. The last few years have witnessed major effort in the developme...

We propose and demonstrate a two dimensional/three dimensional hybrid channel AlGaN/GaN high electron mobility transistor (HEMT) structure with a flat transconductance profile using polarization-induced channel engineering. A quasi three dimensional electron gas profile with 5–6 nm of vertical channel depth was formed by grading the channel region linearly from GaN to Al0.15Ga0.85 N over 50 Å. ...