• Proceedings of the KSR Conference
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• 2009.05b
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• pp.241-245
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• 2009

High speed train system generates much EMI (electromagnetic interference) by arc between the pantograph and the trolley line during the running time. EMI from the tilted EMU train system which is similar to HEMU-400X system for 400 km/h speed and with the distributed engines was measured following EN50121-2, 'Railway applications. - Electromagnetic compatibility (Emission of the whole railway system to the outside world)'. Measured EMI values exceed the limiting values of EN50121-2 in high frequency band ($30\;MHz{\sim}1,000\;MHz$), but exceeding frequencies were identified that they are used for mobile communications. Measured EMI values did not exceed the limiting values in other low frequency band between 9 kHz and 30 MHz.

• Journal of Power Electronics
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• v.19 no.2
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• pp.403-412
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• 2019

Aiming at the problems of large dv/dt and di/dt in traditional single-ended converters and high electromagnetic interference (EMI) noise levels, a single-ended isolated converter using the secondary resonance technique is proposed in this paper. In the proposed converter, the voltage stress of the main power switch can be reduced and the voltage across the output diode is clamped to the output voltage when compared to the conventional flyback converter. In addition, the peak current stress through the main power switch can be decreased and zero current switching (ZCS) of the output diode can be achieved through the resonance technique. Moreover, the EMI noise coupling path and an equivalent model of the proposed converter topology are presented through the operational principle of the proposed converter. Analysis results indicate that the common mode (CM) EMI noise and the differential mode (DM) EMI noise of such a converter are deduced since the frequency spectra of the equivalent controlled voltage sources and controlled current source are decreased when compared with the traditional flyback converter. Furthermore, appropriate parameter selection of the resonant circuit network can increase the equivalent impedance in the EMI coupling path in the low frequency range, which further reduces the common mode interference. Finally, a simulation model and a 60W experimental prototype of the proposed converter are built and tested. Experimental results verify the theoretical analysis.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.14 no.6
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• pp.452-460
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• 2021

As the global electric vehicle (EV) market expands, eco-friendly EV that complement performance and safety problems continue to be released and the market is growing. However, in the case of EVs, the inconvenience of charging, safety problems such as electric shock, and electromagnetic interference (EMI) problems caused by the interlocking of various electronic components are problems that must be solved in EVs. The use of wireless power transmission technology can solve the problem of safety by not dealing with high current and high voltage directly and solving the inconvenience of charging EVs. In this paper, in order to reduce EMI a wireless charging control module, which is a key electronic component of WPT of EV. EMI reduction was designed through simulation of problems such as resonance and impedance that may occur in the power supply and signal distortion between high-speed communication that may occur in the signal part. Therefore, through the EMI reduction design with power integrity and signal integrity, the WPT wireless charging control module for electric vehicles reduces 10 dBu V/m and 15 dBu V/m, respectively, in 800 MHz to 1 GHz bands and 1.5 GHz bnad.

• Journal of Advanced Navigation Technology
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• v.27 no.6
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• pp.798-803
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• 2023

In the industrial internet of things (IIoT) industry, including smart factories, there are many cases where electronic devices are complexly combined and installed due to the recent development of intelligent information technology. Electromagnetic waves generated from such complex facilities affect other devices and services, which can lead to safety issues. The problem such as electromagnetic interference (EMI) and electromagnetic compatibility (EMC) generated when controlling complex facilities is an essential element that must be solved, and the engineering basis for EMI and EMC must be established to foster the industry of complex facilities. Therefore, in this study, EMC & EMI engineering demonstration cases for solar power fixed facilities using the national standard guideline have been analyzed. The results show that the electromagnetic risk indices in the solar power facilities have been degraded up to control level, and a national EMC engineering system has been proposed for complex facilities.

• JSTS:Journal of Semiconductor Technology and Science
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• v.14 no.4
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• pp.471-477
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• 2014

In this paper, a modeling and co-simulation methodology is proposed to predict the radiated electromagnetic interference (EMI) from on-chip switching I/O buffers. The output waveforms of I/O buffers are simulated including the on-chip I/O buffer circuit and the RC extracted on-chip interconnect netlist, package, and printed circuit board (PCB). In order to accurately estimate the EMI, a full-wave 3D simulation is performed including the measurement environment. The simulation results are compared with near-field electromagnetic scan results and far-field measurements from an anechoic chamber, and the sources of emission peaks were analyzed. For accurate far-field EMI simulation, PCB power trace models considering IC switching current paths and external power cable models must be considered for accurate EMI prediction. With the proposed EMI simulation model and flow, the electromagnetic compatibility can be tested even before the IC is fabricated.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.25 no.10
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• pp.966-982
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• 2014

This paper presents recent trends in system-level EMC investigation and countermeasure technology for radio frequency interference (RFI) influenced by noise generated in high-speed digital system. Recently, as the only digital device can perform various roles, there are a variety of EMI/EMC problems between systems. Especially, RFI is now recognized as a major problem, which occurs by EMI caused by the digital system. Therefore, in this paper, recent trends of RFI investigation from component-level to system-level are introduced and analyzed. Furthermore, in order to solve the RFI problem, recent researches are presented and investigated for the occurrences and suppression methods of common-mode noise which is one of the major noise sources in high-speed digital system. Lastly, this paper suggested future research of system-level EMC analysis and countermeasure technology for RFI problems.

• Journal of Powder Materials
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• v.31 no.1
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• pp.57-76
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• 2024

Recent advancements in electronic devices and wireless communication technologies, particularly the rise of 5G, have raised concerns about the escalating electromagnetic pollution and its potential adverse impacts on human health and electronics. As a result, the demand for effective electromagnetic interference (EMI) shielding materials has grown significantly. Traditional materials face limitations in providing optimal solutions owing to inadequacy and low performance due to small thickness. MXene-based composite materials have emerged as promising candidates in this context owing to their exceptional electrical properties, high conductivity, and superior EMI shielding efficiency across a broad frequency range. This review examines the recent developments and advantages of MXene-based composite materials in EMI shielding applications, emphasizing their potential to address the challenges posed by electromagnetic pollution and to foster advancements in modern electronics systems and vital technologies.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.7 no.1
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• pp.36-42
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• 1996

In general, EMI(electromagnetic interference) from EHV(extra high voltage) power lines above 50kV cause interference to AM radio and low VHF television reception. This paper describes the results of long-term measurement of RI and TV1 in 765kV, double circule of $6\times29.59mm$(1.65k inches) diammer $480mm^{2}$(Rail) ACSR conductors in suitable for 766kV transmission lines to provide acceptable EMI at 15m fro the beneath of outmost phase.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.19 no.2
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• pp.263-270
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• 2008

In this paper, we investigated EMI(electromagnetic interference) reduction by conductor connection, which was used for fixing and electrical grounding between frames. Conductor connects two frames and then it provides the decrease of return path of signal current. To prove the effect of conductor, we measured/simulated the RE(radiated emission) with/without conductors between the two frames. From the measured/simulated results, we observed that EMI decreased about 1$\sim$10 dB at the frequency range of 30 MHz to 1 GHz. VNA(vector network analyzer) was used to measure the S parameters and the RE was measured in a 3 m anechoic chamber. The simulated and measured results are compared and discussed.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.19 no.3
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• pp.376-383
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• 2008

Generally a return current plane(RCP) of high speed digital and analog part is partitioned. This is achieved in order to decrease the noise interference between subsystem in PCBs(Printed Circuit Boards). However, when the connected signal line exists between each subsystem, this partition will cause unwanted effects. In a EMI(Electromagnetic Interference) point of view, the partition of the return current plane becomes a primary factor to increase the radiated emission. Component bridge(CB) is used for the way of maintaining radiated emission, still specific user's guide doesn't give sufficient principle. In a view point of EMI, design principle of multi-CB using method will be analyzed by measurement. And design principle of noise mitigation will be provided. Generally interval of multi-CB is ${\lambda}/20$ ferrite bead. In this study, When multi-CB connection is applied, design principle of ferrite bead and chip resistor is proved by measurement. Multi-connected chip resistance$(0{\Omega})$ is proved to be more effective design method in the point of EMI.