A5024203666- GaN-based semiconductor devices and materials
- Radio Frequency Integrated Circuit Design
- Semiconductor Quantum Structures and Devices
- Advanced Power Amplifier Design
- Semiconductor materials and devices
- Mechanical Behavior of Composites
- Epoxy Resin Curing Processes
- Fiber-reinforced polymer composites
- Synthesis and properties of polymers
- Photonic and Optical Devices
- Ga2O3 and related materials
- Electrodeposition and Electroless Coatings
- TiO2 Photocatalysis and Solar Cells
- Gyrotron and Vacuum Electronics Research
- Advancements in Photolithography Techniques
- Gas Sensing Nanomaterials and Sensors
- Semiconductor Lasers and Optical Devices
- Advanced Photocatalysis Techniques
- Structural Analysis of Composite Materials
- Advanced optical system design
- Integrated Circuits and Semiconductor Failure Analysis
- Electronic Packaging and Soldering Technologies
- Silicone and Siloxane Chemistry
- Silicon Carbide Semiconductor Technologies
- Advanced MEMS and NEMS Technologies
Mitsubishi Electric (Japan)
2005-2025
Osaka Prefecture University
2023-2025
Mitsubishi Electric (United States)
2017-2023
Osaka University
2009
Mitsubishi Electric (Germany)
2007-2008
Mitsubishi Group (Japan)
2008
Materials with monolithic structures, such as epoxy monoliths, are used for a variety of applications, column fillers in gas chromatography and HPLC, separators lithium-ion batteries, precursor polymers monolith adhesion. In this study, we investigated the fabrication monoliths using 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane (TETRAD-C) tetrafunctional 4,4′-methylenebis(cyclohexylamine) (BACM) amine curing agent to control pore diameters polyethylene glycols (PEGs) differing molecular...
ABSTRACT Conductive pastes have been used to bond semiconductors and create electrical circuits, but in recent years their use has expanded include flexible substrates portable wearable electronic devices that require high stretchability. using metals, carbons, etc. problems such as the need add large amounts of filler insufficient mechanical strength poor heat resistance binder polymer material. Recently, epoxy monolith a new material developed achieve elongation by introducing porous...
Summary form only given, as follows. This paper describes a high efficiency and output power GaN amplifier for C-band space applications. The uses on-chip harmonic tuned FETs to improve efficiency. A 2nd input tuning circuit is incorporated into each unit FET cell realizes highly precise control of impedance. 100 W with 4-chips achieves 67.0% PAE at 3.7 GHz. To the best our knowledge, this highest amplifiers.
We applied a Cat-CVD (catalytic chemical vapor deposition) passivation film to AlGaN/GaN HEMTs, resolve the trade-off between their drain current transient time and gate-drain break down voltage. did not employ any field plate because it degrades high frequency operation over C-band. The SiN film, deposited after NH3 treatment, resulted in less gate leakage than conventional PE-CVD passivation. A T-shaped HEMT fabricated by this technique, with Lg = 0.4 µm Wg 50.4 mm, delivered an output...
In this paper, GaN HEMT high power amplifiers operating at C-band are presented. Improvement of device performance and reduction thermal resistance with larger gate pitch enabled 1.4 times density compared the previous work [1]-[2]. 167 W output was extracted from a single chip 7 W/mm density. 2-chip amplifier have recorded 220 C-band, which is highest ever reported for higher bands.
Abstract While epoxy resins exhibit excellent mechanical and insulating properties as well stability against heat chemicals, adhesives also have drawbacks such brittleness stress concentration. Rubber-based materials are often added to increase toughness, but they sensitive moisture, limiting their effectiveness in harsh environments. In this study, we propose a new sheet-type adhesive consisting of conventional liquid an monolith sheet with internal continuous pores, using the advantageous...
An X-band high efficiency GaN internally-matched FET has been developed. Asymmetric matching circuit layout is employed to avoid decrease of caused by impedance mismatch and unbalance power dividing in circuits. The designed asymmetric input output circuits have achieved equal characteristics. A added (PAE) 43.4% an 47.8 dBm (60.3 W) with the developed FET.
The strength of adhesives and adhesive joints degrade due to changes occurring in terms environmental heat, moisture, temperature conditions experienced during use. Adhesives with a sea-island phase separated structure consisting hard soft domains, are designed improve reliability when it comes adhesion. In this study, we investigated the structures processes repeated moisture absorption desorption for two commercially available adhesives. We measured epoxy acrylic containing elastomers...
This is the first report of catalytic vapor deposition (Cat-CVD) passivated AlGaN/GaN HEMT. We have found out that Cat-CVD passivation film with NH3 treatment greatly enhances reliability It rationalized, through low frequency capacitance-voltage measurement, in reactor before SiN minimizes damage at SiN/AlGaN interface, leading to reducing surface trap density. The HEMT by suppresses degradation an output power less than 0.4 dB under RF operation Vd = 30 V, f 5 GHz after 200 h.
We demonstrate that Franz-Keldysh oscillations (FKOs) observed by photoreflectance (PR) spectroscopy are highly sensitive to the surface morphology of AlxGa1−xN layers in AlxGa1−x N heterostructures. Three Al0.2Ga0.8N/GaN heterostructures with different surface-morphology profiles, which confirmed atomic force microscopy, have been investigated. The X-ray-diffraction patterns hardly affected Al0.2Ga0.8N/GaN-layer morphology. In contrast, it is revealed cracks and pits dominating remarkably...
We have succeeded in developing three techniques, a precise lens-alignment technique, low-loss built-in Spatial Multiplexing optics and well-matched electrical connection for high-frequency signals, which are indispensable realizing compact high-performance TOSAs ROSAs employing hybrid integration technology. The lens position was controlled to within ±0.3 µm by high-power laser irradiation. All components comprising the multiplexing bonded prism, enabling insertion loss be held down 0.8 dB...
Two precise lens-assembly techniques based on the adhesive bonding and hammering are proposed. These allow us to realize a compact 100GbE TOSA 15.1 × 6.5 5.6 mm which is suitable for QSFP28 form factor. The measured DC output powers more than +4.0 dBm fully achieve target value of+1.0 with large margin.
データセンタ向け光サブアセンブリの高速化のため,ハイメサ構造を有するEMLと電気信号の反射を抑制した高速の電気インタフェース技術を開発した。EMLは従来構造に対して13 GHzの広帯域化を図り,約48 GHzの電気通過帯域を実証した。また,電気インタフェース部であるPCBとFPCの接続部において,50 GHzの帯域で12 dB以下の反射に抑制することに成功した。これら技術を適用した43 Gb/s EML光サブアセンブリを試作,評価した結果マスクマージン11%以上の良好な光波形を得ることができた。さらに,4つのEMLを1つのパッケージ内に集積した424 EML光サブアセンブリを試作,評価した結果,全レーンにおいてTECQ 2.5 dB以下の良好な光波形品質を得ることに成功した。
Abstract We demonstrate that photoluminescence‐excitation (PLE) spectroscopy is applicable to probe effects of the surface damages on carrier transport in Al x Ga 1–x N/GaN heterostructures by systematically characterizing as‐grown and plasma‐exposed samples. The characterization morphology with atomic force microscopy clarifies plasma exposure modifies steps pits N surface. PLE spectrum sample measured at energy photoluminescence from GaN layer shows a step rising fundamental transition...