A5035864719- GaN-based semiconductor devices and materials
- Radio Frequency Integrated Circuit Design
- Semiconductor materials and devices
- Semiconductor Quantum Structures and Devices
- Advancements in Semiconductor Devices and Circuit Design
- Microwave Engineering and Waveguides
- Silicon Carbide Semiconductor Technologies
- Ga2O3 and related materials
- Advanced Power Amplifier Design
- Organic Electronics and Photovoltaics
- Organic Light-Emitting Diodes Research
- Semiconductor Lasers and Optical Devices
- Renal and Vascular Pathologies
- Semiconductor materials and interfaces
- Photonic and Optical Devices
- Vascular anomalies and interventions
- Superconducting and THz Device Technology
- Phytochemistry and biological activity of medicinal plants
- Vascular Procedures and Complications
- Abdominal Trauma and Injuries
- Internet of Things and Social Network Interactions
- Soft tissue tumor case studies
- Breast Lesions and Carcinomas
- Plasma Diagnostics and Applications
- Neuroscience and Neuropharmacology Research
Electronics and Telecommunications Research Institute
2015-2025
Presbyterian Medical Center
2021-2024
Korea Institute of Brain Science
2023
Korea Institute of Science and Technology
2023
Wonkwang University
2014-2020
Gyeongsang National University
2005-2009
Iridium complexes containing cyclometalated 2-cyclohexenylpyridine derivatives with rigid and bulky cyclohexene units are synthesized, found to be highly efficient materials in EL devices (see figure). Devices based on these iridium emit yellowish- green light the very high external quantum efficiency of 18.7%.
Microwave low-noise performance AlGaN/GaN HEMT on a SiC substrate with wide head double-deck T-shaped gate has been reported. The HEMTs gate-length ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$L_{\mathrm { {g}}})$ </tex-math></inline-formula> of notation="LaTeX">$0.17~\mu \text{m}$ and source–drain spacing {sd}}})$ notation="LaTeX">$3.5~\mu exhibited maximum extrinsic transconductance 360 mS/mm,...
This letter presents a gallium nitride (GaN) high electron mobility transistor (HEMT)-based three-stage low noise amplifier (LNA) monolithic microwave integrated circuit (MMIC) that can apply to the fifth-generation (5G) new radio base station applications. The designed GaN-based LNA MMIC utilizes hybrid-matching topology with double-shunt capacitors at input and output (I/O) matching networks achieve broad return loss (RL) bandwidth characteristics across 5G frequency range two bands....
Abstract The effects of the parasitic gate capacitance and resistance ( R g ) on radiofrequency (RF) performance are investigated in L G = 0.15 μm GaN high‐electron‐mobility transistors with T‐gate head size ranging from 0.83 to 1.08 μm. When device characteristics compared, difference DC is negligible. RF terms current‐gain cut‐off frequency f T maximum oscillation max substantially depend size. For clarifying dependence, small‐signal modeling conducted extract . reduced μm, increases by...
Abstract Tau oligomers play critical roles in tau pathology and are responsible for neuronal cell death transmitting the disease brain. Accordingly, preventing oligomerization has become an important therapeutic strategy to treat tauopathies, including Alzheimer’s disease. However, progress been slow because detecting cellular context is difficult. Working toward tau-targeted drug discovery, our group developed a tau-BiFC platform monitor quantify oligomerization. By using platform, we...
This study investigates the operating characteristics of AlGaN/GaN high-electron-mobility transistors (HEMTs) by applying HfO2 as passivation layer. Before analyzing HEMTs with various structures, modeling parameters were derived from measured data fabricated HEMT Si3N4 to ensure reliability simulation. Subsequently, we proposed new structures dividing single into a bilayer (first and second) first layer only. Ultimately, analyzed compared operational considering basic Si3N4, only HfO2,...
A compact-size and low-cost tunable external cavity laser transmitter optical sub-assembly with butt-coupled superluminescent diode polymer Bragg reflector (PBR) is described. The output wavelength of the widely tuned over 16 nm by a heater PBR finely phase PBR. threshold current power slope are 8 mA 0.117 W/A, respectively, at temperature 25 <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex...
This study investigates the operational characteristics of AlGaN/GaN high-electron-mobility transistors (HEMTs) by applying a slant-gate structure and drain-side extended field-plate (FP) for improved breakdown voltage. Prior to analysis slant-gate-based HEMT, simulation parameters were extracted from measured data fabricated basic T-gate HEMTs secure reliability results. We suggest three different types structures that connect electrode boundary 1st 2nd SiN passivation layers obliquely. To...
In this study, we propose an optimized AlGaN/GaN high-electron-mobility transistor (HEMT) with a considerably improved breakdown voltage. First, matched the simulated data obtained from basic T-gate HEMT measured fabricated device to ensure reliability of simulation. Thereafter, improve voltage, suggested applying gate-head extended structure. The gate-head-top and gate-head-bottom lengths were symmetrically by 0.2 μm steps up 1.0 μm. voltage structure was 52% higher than that HEMT. However,...
(2009). Efficient white phosphorescent organic light‐emitting diodes for solid‐state lighting applications using an exciton‐confining emissive‐layer structure. Journal of Information Display: Vol. 10, No. 2, pp. 92-95.
Desmoplastic fibroma of bone is a rare locally aggressive, but non-metastatic tumor.In this case report, we present desmoplastic in an unusual location, the clavicle.Desmoplastic involving clavicle extremely rare, with only 2 reported cases before 1985.We report imaging findings review relevant literature.
Abstract We have developed an InAlAs/InGaAs metamorphic high electron mobility transistor device fabrication process where the gate length can be tuned within range of 0.13 μm–0.16 μm to suit intended application. The core processes are a two‐step electron‐beam lithography using three‐layer resist and recess etching citric acid. An was fabricate T‐shaped electrode with fine foot relatively large head. This realized through use three‐layered beam exposure development. Citric acid‐based is wet...
The 0.15 /spl mu/m gate-length power metamorphic HEMTs (MHEMT) with wide head T-shaped gate has been fabricated and the DC, microwave, noise performance of device were characterized. MHEMT shows DC output characteristics having an extrinsic transconductance 740 mS/mm a threshold voltage -0.75 V. f/sub T/ max/ obtained for times/ 100 pm are 150 GHz 240 GHz, respectively. MHEMTs exhibit minimum figure, NF/sub min/, 0.79 dB associated gain 10.5 at 26 GHz. min/ measured 40 is 1.21 6.41 dB. This...
A MMIC chip set consisting of a power amplifier, driver low noise and frequency doubler has been developed for automotive radar systems at 77GHz. The was fabricated using 0.15 /spl mu/m gate-length InGaAs/InAlAs/GaAs mHEMT process based on 4-inch substrate. amplifier demonstrated measured small signal gain over 20 dB from 76-77GHz with 15.5 dBm output power. size is 2mm times/ 2mm. exhibited 23dB 76-77 GHz band an 13dBm. 2.1mm achieved in between 10 dBm. 2.2mm -6 76.5 conversion -16dB input...
A single supply, high linearity, efficient power devices and amplifier MMIC is implemented utilizing performance of quasi-enhanced PHEMT technology. The device features Vth= -0.65 V, Vbdg=26 Imax=144 mA/mm at Vgs=0.2 Gm=340 mS/mm. When matched on-wafer compromise between efficiency, the OIP3 peak IP3 40.5 dBm for 2 GHz 37.0 5.8 GHz, respectively. achieves Pout=27 with associated PAE=45% 5 V under Vgs=0 GL=14.5 dB, OIP3=37.5 dBm.
This study proposes an approach to enhance frequency characteristics for AlGaN/gallium nitride (GaN) high-electron-mobility transistors (HEMTs) by employing air-bridged source-connected field plate asymmetric passivation structure. To overcome simulation limitations, we performed the device matching simulated results with measured data, applying various models, and performing comparative analysis of between calculated values using a small-signal equivalent circuit. Thus, were well matched...
ABSTRACT This article describes the successful development and performance of X‐band 100 W pulsed SSPA using a 25 GaN‐on‐SiC high electron mobility transistor (HEMT). The GaN HEMT with gate length 0.25 µm total width 8 mm were fabricated. provide linear gain dB output power operated at 30 V drain voltage in continuous wave (CW)‐operation added efficiency 43% X‐band. It also shows maximum density 3 W/mm. exhibited an (50 dBm) 53 frequency range 9.2–9.5 GHz. are suitable for radar systems...
We developed a 0.1-μm metamorphic high electron mobility transistor and fabricated W-band monolithic microwave integrated circuit chipset with our in-house technology to verify the performance usability of technology. The DC characteristics were drain current density 747 mA/mm maximum transconductance 1.354 S/mm; RF cutoff frequency 210 GHz oscillation 252 GHz. A multiplier was increase input signal. showed output values (more than 0 dBm) in 94 GHz–108 band achieved excellent spurious...