• Proceedings of the IEEK Conference
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• 2006.06a
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• pp.65-66
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• 2006

In this paper, we designed and fabricated a broadband antenna for EMI site validation above 1 GHz. To develop the antenna which is satisfied omni-directional radiation pattern and broadband characteristics required by CISPR, we designed biconical type with cylindrical load. The developed antenna has good characteristics of the radiation patterns and VSWR<2 the frequency range from 1 GHz to 18 GHz.

• Journal of the Institute of Convergence Signal Processing
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• v.3 no.2
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• pp.45-52
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• 2002

EMI(Electromagnetic Interface) is a measure of electomagnetic radiation from equipment in the range of 10KHz to 3GHz, and can cause unexpected reactions of electronics/electrical equipment. In this study, for safe and stable communication operation, a STGU(System Timing Genetation Unit), which is a 2.5Gbps SDH System and a major EMI source, was employed to simulate electromagnetic interface. In On-Site test, the power of fundamental frequency of EMI of interest and its harmonics were measured. Also, a low pass filter at cut-off frequency of 2GHz was specifically designed to minimize the effect of EMI between electronic components. When the low pass filter was implemented within the STGU, the power of EMI decreased more than 20dBm. Finally, when TIE and MTIE, two important quality measure in synchronous reference clcok, was assessed, ITU-T G8l3 requirements are satisfied.

• Journal of the Korea Society for Simulation
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• v.10 no.4
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• pp.21-30
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• 2001

In this paper, EMI measurement, the STGU simulation being conducted, filter design, its characteristics, and its implementation to the PCB, and finally test results are discussed. When the low pass filter was implemented within the STGU, the power of EMI decreased more than 20dBm. Finally, when TE and MTIE, two important quality measure in synchronous reference clock, was assessed, ITU-T G813 requirement was satisfied. EMI(Electromagnetic Interface) is a measure of electomagnetic radiation from equipment in the range of 10KHz to 3GHz, and can cause unexpected reactions of electronics/electrical equipment. In this study, for safe and stable communication operation, a STGU (System Timing Generation Unit), which is a 2.5G SDH System and a major EMI source, was employed to simulate electromagnetic interface. Using Open-Site test, the power of fundamental frequency of EMI of interest and its harmonics were measured. Also, a low pass filter at cut-off frequency of 2GHz was specifically designed for this study to minimize the effect of EMI between electronic components.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2001.05a
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• pp.244-248
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• 2001

According to the progress of the electronic industry and radio communication technologies, mankind might enjoy its abundant life. On the other hand, many social problems such as EMI, and unnecessary electromagnetic wave occur due to the increased use of electromagnetic wave. Therefore, the organizations such as CISPR, FCC, ANSI, etc. have provided the standard of electromagnetic wave environment for the countermeasure of the EMC. It had been required that the absorbing ability of an electromagnetic wave absorber is more than 20dB, the bandwidth of which is required through 30 MHz to 1,000 MHz for satisfying the international standard about an anechoic chamber for EMI/EMS measurement. From November of 1998, however, the CISPR11 has accepted the extended frequency band from 1 GHz to 18 GHz additionally in the bandwidth of EMI measurement[1]. In this paper, we proposed a new type absorber satisfying the above requirements and carried out broadband design using the equivalent material constants method. Futhermore, the experiments were carried out over the frequency band from 30 MHz to 2 GHz, and hence, the validity of the proposed design theory was confirmed.

• Journal of the Korean Society of Clothing and Textiles
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• v.23 no.5
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• pp.694-702
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• 1999

By using commercial available electromagnetic interference (EMI) shielding fabrics, EMI shielding effectiveness(SE) and the physical properties were investigated. Thirteen specimens were chosen six fabrics were non-electrolytic plated with Cu, six plated with Cu+Ni and one plated with Ni, SE was measured by RF Impedance Analyzer HP4291A(Hewlett Co, Ltd)at the frequency of 100MHz-1.8GHz. The results showed that the commercial EMI shielding fabrics provided SE values over 30dB at the frequency of 100MHz-1.8GHz. Fabrics plated with Cu showed more effective shielding than those plated with Ni. The thickness of coating and fabric count were also influential factors on SE. Tensile properties were acceptable for lining fabrics but water vapor transport properties indicated that the better treatment condition were suggested to improve comfort properties.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.5 no.4
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• pp.798-806
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• 2001

As electronic industry and radio communication technologies progress, the electrical and electronic equipments are lightened, minimized, and operated by low power. At the same time, these equipments react sensitively by electromagnetic wave noise. It is a origine these equipments to wrong-operation. In this paper, we focused on the design and preperation condition of a advanced EMI filter. This filter sowed superior attenuation effect of 10 dB~20 dB compare with typical filter in the range of frequency from 150 kHz to 30 GHz and superior character over the variation of a load.

• Journal of electromagnetic engineering and science
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• v.8 no.1
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• pp.1-5
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• 2008

In this paper, a biconical type antenna is proposed for EMI test site validation above 1 GHz. To achieve broadband and omni-directional radiation patterns required by international standard(CISPR), the proposed antenna consists of general bicones with cylindrical loads and adopts side feeding method to minimize the influence on H-plane pattern due to feeding cable, balun, and connector. The radiation patterns of the fabricated antenna are measured and the results are compared with CISPR criteria and commercial antenna in our interest frequencies. Although the proposed antenna has a few problems in frequency range of 1 GHz to 2 GHz, it has relatively better performance than commercial antenna.

• 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.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.16 no.1 s.92
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• pp.56-65
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• 2005

We proposed the Power-line EMI filter for vehicle-shelter which have attenuation performance of 100 dB from 10kHz to 1 GHz. The inductor and capacitor for EMI filter design was charactenzed using circuit simulator and then, we experimentally verified 100 dB attenuation for the conducted emission noise through power line. This results will be used for the application systems of protection weapons against EMI attacks as well as vehicle-shelter.

• Carbon letters
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• v.22
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• pp.36-41
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• 2017

Biodegradable epoxy (B-epoxy) was prepared from diglycidyl ether of bisphenol A and epoxidized linseed oil. The mechanical properties of B-epoxy composites reinforced with multi-walled carbon nanotubes (MWCNTs/B-epoxy) were examined by employing dynamic mechanical analysis, critical stress intensity factor ($K_{IC}$) tests, and impact strength tests. The electromagnetic interference shielding effectiveness (EMI-SE) of the composites was evaluated using reflection and absorption methods. Mechanical properties of MWCNTs/B-epoxy were enhanced with an increase in the MWCNT content, whereas they deteriorated when the MWCNT content was >5 parts per hundred resin (phr). This can likely be attributed to the entanglement of MWCNTs with each other in the B-epoxy due to the presence of an excess amount of MWCNTs. The highest EMI-SE obtained was ~16 dB for the MWCNTs/B-epoxy composites with a MWCNT content of 13 phr at 1.4 GHz. The composites (13 phr) exhibited the minimum EMI-SE (90%) when used as shielding materials at 1.4 GHz. The EMI-SE of the MWCNTs/B-epoxy also increased with an increase in the MWCNT content, which is a key factor affecting the EMI-SE.