The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
This paper describes suppression of current collapse by field-plate (FP) in AlGaN/GaN MOS-HEMTs. Current collapse reduction was confirmed for a multi-gate fingered MOS-HEMT with a total gate width of 10 mm. Moreover, we have fabricated a 5-A class MOS-HEMT with both gate-FP and source-FP (dual-FP), showing more complete suppression in current collapse as compared to that with only gate-FP.
This paper describes breakdown characteristics of AlGaN/GaN high electron mobility transistors (HEMTs) with multi-finger gate patterns. We studied the spatial profile of electroluminescence (EL) from AlGaN/GaN HEMTs under high drain and near pinch-off gate bias. As a result, different EL emission profiles and breakdown characteristics were observed depending on the drain electrode pattern of the devices.
This paper describes the effect of thickening Au-plated ohmic electrodes in AlGaN/GaN HEMTs on the drain current and on-resistance. By increasing the thickness of Au-plated ohmic electrodes up to 5 µm, the fabricated AlGaN/GaN HEMT with a total gate width from 2 to 10 mm exhibited an increase in the maximum drain current by about 50 % and a reduction in the on-resistance by more than 40 %.
The high-frequency characteristics of high electron mobility transistors applying AlGaN for a channel layer (AlGaN channel HEMTs) with greater impacts of alloy disorder scattering than those in conventional HEMTs with a GaN channel layer (GaN channel HEMTs) are investigated. The obtained electron saturation velocity was 4.7 × 106 cm/s and the cutoff frequency was 7 GHz in the AlGaN channel HEMTs with...
In this study, the counting rate performance of a newly developed Compton camera for biological and medical applications was investigated; further, the sensitivity profile of this highly complicated imaging system was measured using 22Na and 18F point gamma-ray sources. 22Na was used to assess the imaging ability of this camera against the point source, and the intense 18F point source of 200 MBq...
In this paper, we report the estimations of the lower detection limits of gamma ray energy for a newly developed Compton camera for applications to nuclear medicine imaging. We performed simulation studies to investigate the relationship of the distance between the scatterer and absorber detectors with the lower detection limit. In addition, imaging tests were performed by using multiple sources.
This paper presents an experimental investigation on the wideband intermodulation distortion compensation characteristics of a 3.5-GHz feed-forward power amplifier for mobile base stations. The fabricated 3.5-GHz band 140-W class feed-forward power amplifier employing gallium nitride high electron mobility transistors (GaN HEMTs) achieves the intermodulation distortion compensation bandwidth of 160...
This paper presents a 2-GHz band gallium nitride (GaN) high electron mobility transistor (HEMT) amplifier cryogenically cooled to 60 K as a part of the cryogenic receiver front-end (CRFE) for mobile base station receivers. The GaN HEMT amplifier attains the output power of 3 W and the maximum power added efficiency of 62% with a 50 V drain bias for class-AB operation. The results reported herein are...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.