A5033063072- Radio Frequency Integrated Circuit Design
- Semiconductor Quantum Structures and Devices
- GaN-based semiconductor devices and materials
- Semiconductor materials and devices
- Advancements in Semiconductor Devices and Circuit Design
- Photonic and Optical Devices
- Microwave Engineering and Waveguides
- Semiconductor Lasers and Optical Devices
- Ga2O3 and related materials
- Advanced Power Amplifier Design
- Silicon Carbide Semiconductor Technologies
- Advancements in PLL and VCO Technologies
- Superconducting and THz Device Technology
- Semiconductor materials and interfaces
- Physics of Superconductivity and Magnetism
- Advanced Photonic Communication Systems
- Terahertz technology and applications
- Advanced Semiconductor Detectors and Materials
- Millimeter-Wave Propagation and Modeling
- Integrated Circuits and Semiconductor Failure Analysis
- Microwave Dielectric Ceramics Synthesis
- ZnO doping and properties
- Geology and Paleoclimatology Research
- ICT Impact and Policies
- Inorganic Chemistry and Materials
Fujitsu (China)
2008-2025
Fujitsu (Japan)
2012-2024
The University of Tokyo
1989-2023
Yokohama Rosai Hospital
2021
Hokkaido University
2017
Fujitsu (United States)
2012-2016
Kobe University
2016
Doshisha University
2013
University of Toyama
2013
University of Tsukuba
1990-2011
This letter presents details of high-performance enhancement-mode GaN MIS high-electron-mobility transistor (MIS-HEMT) devices. Devices with an n-GaN/i-AlN/n-GaN triple cap layer, a recessed-gate structure, and high- <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">k</i> gate dielectrics show high drain current complete operation. The maximum threshold voltage ( xmlns:xlink="http://www.w3.org/1999/xlink">V</i> <sub...
The Japanese Clinical Practice Guidelines for Management of Sepsis and Septic Shock 2020 (J-SSCG 2020), a Japanese-specific set clinical practice guidelines sepsis septic shock created as revised from J-SSCG 2016 jointly by the Society Intensive Care Medicine Association Acute Medicine, was first released in September published February 2021. An English-language version these based on contents original Japanese-language version. purpose this guideline is to assist medical staff making...
Abstract In this paper, a current status and future technologies of high‐power GaN HEMTs was described. First, commercialization roadmap shown with output power efficiency status. Power electronics benchmark also introduced. Reliability improvement were addressed recent issues such as drift phenomena. Then, requirements for expanding market some device developments. Novel E‐mode recessed GaN‐HEMT has been developed using the triple cap layer structure. High‐k insulated gate Ta 2 O 5...
A high maximum frequency of oscillation (f <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">max</sub> ) 910 GHz was achieved at InAlAs/InGaAs highelectron mobility transistors (HEMTs) with a relatively long gate length (L xmlns:xlink="http://www.w3.org/1999/xlink">G</sub> 75 nm by adopting an asymmetric recess and double-side-doped structure. The f improved significantly extending the drain-side xmlns:xlink="http://www.w3.org/1999/xlink">RD</sub>...
(Ca 1- x Nd 2 /3 )TiO 3 sintered samples are fabricated with 0≦ ≦1 and the crystal structure dielectric properties investigated. It is shown that has an orthorhombic GdFeO -type for ≦0.69 La 2/3 TiO double-layered perovskite 0.78≦ ≦0.93. High ε high f Q values obtained phase of , e.g. =108 =17200 GHz =0.39. On other hand, phase, between 80 100 below 1000 GHz.
A time-of-flight neutron diffraction experiment was undertaken on a powder sample of orthorhombic ZrO2 synthesized at 600°C and 6GPa for 30min. The Rietveld analysis the data shows that space group this phase is Pbca. refined lattice parameters are a0=1.00861, b0=0.52615, c0=0.50910nm.
We present 20-Gbps wireless ASK data transmission at 300 GHz with an all-electronic transmitter and receiver for KIOSK instant downloading applications. The MMICs are based on 70-nm indium-phosphide-based high electron mobility transistor technologies of which the cut-off frequency (fmax) is approximately 700 GHz. For experiment, were packaged in a split-block waveguide dedicated metallic housing, respectively. With 30-dBi 25-dBi horn antennas receiver, error free (bit rate < 1 × 10−9) was...
We demonstrate high voltage HFET operation with suppression of gm dispersion and current collapse using an n-type thin GaN cap layer combined SiN passivation a recessed ohmic structure. Polarization-induced surface charge was controlled. Off state on-state breakdown voltages were 140 V 70 V. obtained power HFETs CW 35 without any heat sinking method.
In this paper, we report a C-band power amplifier with over 340-W output using 0.8-mum GaN-HEMTs and an X-band 100-W 0.25-mum GaN-HEMTs. We used two-chip configurations the three-stage impedance transformers to extend bandwidth for both circuits. The input lines adjacent each chip are divided by four suppress non-uniform heat distribution in at high frequencies. As result, obtained 343-W 53-% added efficiency (PAE) 4.8 GHz. This is highest ever reported amplifiers. also 101-W PAE 9.8...
The crystal structure of orthorhombic HfO 2 synthesized at 600°C and 6 GPa was investigated by a time‐of‐flight neutron powder diffraction experiment. Rietveld analysis these data revealed that the space group this phase is Pbca. refined lattice parameters are 0 = 1.00177, b 0.52276, c 0.50599 nm. derived from distorted fluorite (CaF ) ‐glide parallel to ‐axis. hafnium atom in seven‐fold coordination. found be same as an ZrO , which occurs under high pressure above 3 GPa.
This paper presents W-band monolithic microwave integrated circuit (MMIC) amplifiers with grounded coplanar waveguide (GCPW) in 0.12μm GaN HEMT technology. A fabricated four-stage low-noise amplifier (LNA) exhibited a record gain of 23 dB at 76.5 GHz and first reported noise figure (NF) 3.8 80 for any MMIC. Another MMIC power (PA) delivered an output 25.4 dBm continuous wave (CW) operation. To our knowledge, this is the demonstration LNA as well MMICs GCPW W-band. In addition, practical...
In this paper, we describe highly reliable GaN high electron mobility transistors (HEMTs) for high-power and high-efficiency amplifiers. First, present the reliability mechanisms progress on previously reported HEMTs. Next, introduce our specific device structure HEMTs improving reliability. An n-GaN cap optimized buffer layer are used to realize efficiency by suppressing current collapse quiescent (I <sub xmlns:mml="http://www.w3.org/1998/Math/MathML"...
A <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">W</i> -band millimeter-wave transmitter and receiver that are based on impulse radio (IR) architecture were developed. The IR-based apparatuses have an optical-fiber input/output interface board supports multi protocol signals (OC-192 10 GbE) implements a forward error correction (FEC), enabling 10-Gb/s data transmission both in space fiber seamlessly. Analyzing model with simple on/off...
A maximum frequency of oscillation (fmax) 1.3 THz was achieved using an extended drain-side recess structure InAlAs/InGaAs high-electron-mobility transistors (HEMTs), although the gate length relatively long at 75 nm. The high fmax improved by reducing drain output conductance (gd). use asymmetric and double-side doping above below a channel region were effective in gd. Further improvements transconductance (gm) gd distance between source electrodes.
The authors have developed a highly uniform, InP-based high-electron-mobility transistor (HEMT) technology for high-speed optical communication system integrated circuits (ICs). Special attention was paid to obtaining high yield and uniformity without degrading the high-frequency characteristics of these HEMTs. An InP etch-stopper layer employed control gate recess etching. successfully fabricated InAlAs-InGaAs HEMTs with cutoff frequency 175 GHz after interconnection, which is sufficiently...
This paper presents two oscillators (OSCs) and a high power amplifier (PA) for millimeter-wave transceivers. The circuits were designed with grounded coplanar waveguide (GCPW) 0.12-μm GaN HEMT technology. One OSC, which was based on simple series source feedback topology, oscillated at frequency of 74.5 GHz an output 2.2 mW (3.38 dBm). oscillation the highest ever reported OSCs. Another OSC buffer delivered record 85 (19.28 dBm) 70.75 GHz. In addition, single-chip PA 3-stage common scheme...
We analyzed the degradation mode of GaN-HEMTs. observed sudden to make serious influence on reliability. In this paper, we proposed a new approach eliminate sudden-degradation devices. By measuring gate leakage current before stress test, can predict degradation. also discussed factor, for example, surface hexagonal pits. Using eliminating method, could select reliable devices with life over 1 times 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML"...
Abstract A novel piezoelectric‐induced cap structure in an AlGaN/GaN high electron mobility transistor (HEMT) was developed for enhancement‐mode (E‐mode) operation with maximum drain current density ( I dmax ), breakdown voltage BV gd ) and small collapse. Our consists of a thin GaN/AlN/ GaN triple‐layer, which reduces the sheet resistance R sh due to conduction band bending. The threshold V th is +0.25 520 mA/mm, 336 collapse by using gate recess technique. single‐chip E‐mode HEMT amplifier...
A wavelet generator (WG) based on simple ultra-wideband impulse radio (UWB-IR) architecture has been developed to use for multi-gigabit communications systems that utilize the W-band millimeter wave (75–110 GHz). The WG radiates a pulse signal, or wavelet, whose full width at half maximum is less than 80 ps, which makes it possible realize 12.5-Gb/s ON/OFF keying transmitter. consists of only two components: (PG) and band pass filter (BPF). digital-based PG was fabricated by using 0.13-μm...
This paper describes a new preamplifier IC with 0,15-/spl mu/m gate InP-based high electron mobility transistors (HEMTs) for high-speed fiber optic communication system. The consists of lumped-element transimpedance amplifier (TIA) the input stage and highly stabilized distributed cascode-configured unit cells gain stage. A gain-peaking technique was employed to enhance bandwidth flatness preamplifier. peaking profile compensates lack TIA. As result, we achieved flat 52 dB/spl Omega/ 49 GHz.
Abstract In this paper, we reported on a technology to improve the three‐terminal breakdown voltage of GaN high electron mobility transistor (GaN‐HEMT) for millimetre‐wave amplifier. To fabricate high‐power and high‐efficiency GaN‐HEMT amplifier, it is necessary pinched‐off current. work, thickness channel layer quality has been improved by adding small quantities Al buffer. We demonstrated maximum frequency oscillation ( f max ) over 200 GHz with current 10 –6 A/mm at V ds 50 device gate...
The effect of energy band control with varying carrier concentration in GaAsSb-based backward diodes was investigated and diode parameters were analyzed to enhance voltage sensitivity. consisted a heterojunction p-GaAs 0.51 Sb 0.49 /i-In 0.52 Al 0.48 As/n-In 0.63 Ga 0.37 0.53 0.47 As, they mostly lattice-matched an InP substrate. degree bending at the depletion layer n-In As varied on basis layer. Voltage sensitivity depends since affects structure junction. parameter analysis indicated that...