A5100705619- Wireless Power Transfer Systems
- Advancements in Semiconductor Devices and Circuit Design
- Semiconductor materials and devices
- Energy Harvesting in Wireless Networks
- Advanced DC-DC Converters
- Radio Frequency Integrated Circuit Design
- Electrical Contact Performance and Analysis
- Silicon Carbide Semiconductor Technologies
- Multilevel Inverters and Converters
- Advanced Battery Technologies Research
- Innovative Energy Harvesting Technologies
- Integrated Circuits and Semiconductor Failure Analysis
- RFID technology advancements
- Silicon Nanostructures and Photoluminescence
- Nanowire Synthesis and Applications
- Thin-Film Transistor Technologies
- Railway Systems and Energy Efficiency
- Transition Metal Oxide Nanomaterials
- CCD and CMOS Imaging Sensors
- GaN-based semiconductor devices and materials
- Induction Heating and Inverter Technology
- Electromagnetic Launch and Propulsion Technology
- Analog and Mixed-Signal Circuit Design
- Safety Systems Engineering in Autonomy
- Silicon and Solar Cell Technologies
University of Seoul
2019-2024
Samsung (United States)
2024
Seoul National University
2008-2019
Samsung (South Korea)
2014
Seoul National University of Science and Technology
2009
Steel-reinforced concrete has been widely used in the construction of railways because its robustness and low maintenance cost. This paper focuses on analysis unwanted losses a reinforced track when high-power online wireless power transfer system is installed it. Induced dielectric loss concrete, eddy current hysteresis reinforcing steel bar are calculated using analytic equations finite-element analysis. Among three sources loss, dominant one identified first sections this paper. It shown...
In this letter, <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">f</i> <sub xmlns:xlink="http://www.w3.org/1999/xlink">max</sub> improvement of a circuit-level radio-frequency (RF) transistor with systematic layout variations is presented in deep-submicrometer CMOS technology. We confirmed that the MOS has tradeoff among extrinsic capacitive and resistive parasitics ( xmlns:xlink="http://www.w3.org/1999/xlink">C</i>...
Solid-state transformers (SSTs) utilize multiple isolated dual-active-bridge (DAB) converters to deliver power from a medium-voltage ac or dc grid low-voltage loads. The DAB converter is key component of SSTs. This study proposes novel SST with loosely coupled resonant DABs (LCR-DAB) utilizing inductive transfer (IPT) coils instead high-frequency (HF) transformers. Unlike HF transformers, the large air gap between primary and secondary enables easier packaging high-voltage insulation...
Because a transmitter-side controller of an inductive power transfer (IPT) system cannot directly measure its load conditions, i.e., receiver-side output voltages and currents, wireless communications are commonly used in many IPT systems. However, the communication can cause devastating failure because tens milliseconds delays frequent data losses. The mismatch between transmitted received destroy converters. In this article, voltage current observers for series–series tuned proposed using...
This paper presents the design of a dynamic vision sensor for mobile applications. The features standby mode with less than 250uW power dissipation. changes operation between and normal itself depending on input activity. consumption in is typically 500uW activity dependent. implemented 90nm backside illumination process pixel-array size 1.44mm by 1.44mm.
This paper proposes a high-bandwidth control structure for solid-state-transformers (SSTs). To fabricate medium-voltage (MV, 25 kV <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">rms</inf> ) SST, 42-level AC/DC rectifier and forty-two dual-active-bridge (DAB) converters are required. However, it is challenging to simultaneously these due synchronization, propagation delay, complexity. In this paper, an optimized MV high-level SST controller...
The effects of hot carrier stress on the characteristics NMOSFETs and low noise amplifier (LNA) in 65 nm CMOS technology are investigated. method determining condition is explained to achieve maximum substrate current where damage generated NMOSFETs. increase threshold voltage caused by carriers leads a drop biasing transistors. These lead decrease transconductance output conductance device. There almost no change subthreshold swing, gate-source gate-drain capacitances. In LNA, power gain,...
Carrier velocity in the MOSFET channel is main driving force for improved transistor performance with scaling. We report measurements of drift electrons and holes silicon inversion layers. A technique extracting effective carrier which a more accurate extraction method based on actual charge measurement used. This gives result over whole range V<SUB>ds</SUB>, because it does not assume linear approximation to obtain limit applicable V<SUB>ds</SUB>. For very short length device, electron...
Previous high power on-line inductive transfer (IPT) systems use line-frequency (LF) transformers and high-frequency (HF) to be compatible with the ratings of commercial switches. However, LF HF make IPT bulky expensive. This study proposes a new transformerless multilevel system using rectifiers, inverters, excitation coils. Instead transformers, series-connected rectifier inverter are used. coils, which have strong magnetic couplings transmitter coil, is connected each output terminals...
For an inductive wireless power transfer system, developing a high-performance controller is very challenging. Because the transmitter cannot directly sense receiver-side voltage and currents, many conventional systems use communication to feedback information transmitter-side controller. However, because of delay frequent data loss causes significant problem in control. Using synchronous reference frame model series-series tuned system which was proposed previous research, current observers...
In this study, the effects of back-gate bias on subthreshold swing (S) a tunnel field-effect transistor (TFET) were discussed. The electrostatic characteristics back-gated TFET obtained using technology computer-aided design (TCAD) simulation and explained concepts turn-on inversion voltages. As result, S decreased, when voltage increased; behavior is attributed to resultant increase in voltage. addition, it was found that on–off current ratio increased with decrease due
Conventional on-line inductive power transfer (IPT) systems use a 60- Hz transformer and rectifier at their front-ends to step down medium-level input voltage (22.9 kV or 25 kV) low of 0.1 - 3 kVrms, so it is compatible with ratings commercial switches. To achieve high output level, multiple inverters high-frequency transformers can be tied in parallel the rectified DC bus. However, 60-Hz are main impediments that make system bulky expensive. This paper proposes new IPT utilizes multilevel...
Loosely-coupled-resonant dual-active-bridge (LCR-DAB) converter substitutes a high-frequency (HF) transformer for inductive power transfer (IPT) coils. An air gap between the IPT coils is advantageous in achieving high-voltage isolation, key technical barrier of medium-voltage (MV) solid-state-transformer (SST) systems. Owing to weak magnetic coupling coils, LCR-DAB requires resonant compensations. This makes unique characteristics compared conventional transformer-coupled DAB converters....
<para xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> In this letter, we investigate the deembedding accuracy of OPEN-SHORT (OS) and PAD-OPEN-SHORT (POS) for transistor measurement modeling. It is found that all intrinsic element values except gate-resistance, <formula formulatype="inline"><tex Notation="TeX">$R_{g}$</tex> </formula>, are independent procedure. Furthermore, difference in </formula> dependent on device size. To analyze origin...
The density of states (DOS) amorphous silicon (a-Si) was extracted by multifrequency Capacitance-Voltage (C-V) characteristics and mobility measurement applied to two dimensional TCAD simulation. It is well known that the DOS definitely influences current TFT devices [1]. Thus, distribution should be primarily considered on In order validate DOS, simulation results were compared experimental data.
A wireless power transfer system for an electric bicycle was investigated in this study. Loosely coupled transmitter and receiver coils that are designed installation on a rack bike wheel were developed. Achieving required mutual inductance with compact size light weight the goal of design. To achieve requirements, wound ferrite pot-core increases coils' self-inductances confines magnetic flux to prevent coupling rack. Using finite element analysis, dependence quality factor self-inductance...
This paper proposes a large-scale, high-power, transformerless, multilevel wireless charging station for electric vehicles (EVs) using rectifier, resonant inverters, and excitation coils. The rectifier converts the medium voltage (MV, 22.9 kV <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">rms</inf> in S.Korea) of electrical grid to 42 levels 1 kV. Forty-two inverters coils generate synchronized magnetic fields induce current transmitter coil....
A solid-state transformer (SST) uses multiple isolated dual-active-bridge (DAB) converters to deliver power from a medium voltage AC or DC grid low loads. The DAB converter is the key component of SST. In this study, new loosely coupled resonant (LCR-DAB) that utilizes inductive transfer (IPT) coils instead high frequency (HF) transformers conventional DABs proposed. Unlike HF transformers, large air-gap between primary and secondary enables easier packaging insulation LCR-DAB. Series-series...
A transformerless multilevel inductive power transfer (IPT) system employs AC/DC and DC/AC converters, multiple excitation coils to build a medium voltage (MV, 22.9 kV <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">rms</inf> or 25 ) grid-tied system. conventional IPT has line-frequency (LF) high-frequency (HF) transformers increase its level. However, the result bulky expensive. Instead of LF HF transformers, are used in systems. The deliver...
A transformerless multilevel inductive power transfer (IPT) system converts a medium-voltage (MV, 22.9 kVrms to low-voltage (LV, 1 kV) using active rectifier and resonant inverters. Excitation coils are connected the output terminals of inverters generate magnetic fields excite voltages currents on transmitter coil. Then, coil generates augmented field induce load receiver via loose couplings between them. However, high voltage isolation is key challenge MV system. An excitation should be...