• Title/Summary/Keyword: 전자파 차폐

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Comparison of SE Evaluation Methods for HEMP Shelters (HEMP 방호시설의 SE 평가방법의 비교)

  • Chung, Yeon-Choon;Lee, Jongkyung;Kwun, Suk-Tai
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.25 no.11
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    • pp.1197-1200
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    • 2014
  • Two test standards to be applied for evaluating shielding effectiveness of HEMP protection facilities, MIL-STD-188-125-1 and IEEE std. 299, provide different test results in spite of the same facility. In particular, at the frequency range of 10 kHz~20 MHz, it is confirmed that the test results by the IEEE Std. 299 are about 20~30 dB lower than the evaluated results by MIL-STD-188-125-1. These results are due to the different measurement conditions specified in the two test standards. Therefore, IEEE Std. 299 can be applied for the shortening of test distance, but the required SE performance based on MIL-STD-188-125-1 must be modified.

Electromagnetic Wave and EMF Attenuation by Shielding Materials in home appliances (가전제품 전자파 현황 및 차폐재에 의한 감쇄 효과)

  • Cho, Jae-Cheol;Park, Jae-Hwan
    • Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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    • v.9 no.6
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    • pp.711-718
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    • 2019
  • Spectrum analyzer and electromagnetic field meter were used to investigate the EM generation behaviour in different types of home electrical appliances. During microwave oven operation, the EM power measured at a point 30cm apart was measured in the range of 8~11mW/㎡, the strength of the low frequency magnetic field was 60~80mG and the electric field strength was measured at 150~160V/m. For smart phone wireless charging pad, it was measured at an electromagnetic power of 0.4mW/㎡, an electric field of 160 V/m and a magnetic field of 1mG at a point 10cm away. For microwave oven and wireless charging pad, if used within 10cm, the size of the electric field has been measured at a large value that exceeds the human body protection standard and may be hazardous to humans. On the other hand, home appliances such as TVs, hairdryers and refrigerators all showed very low levels of electromagnetic waves, electric fields and magnetic fields, with no harmful effects seen. For electromagnetic shielding, the metal Cu fabric and metal foil had a high level of EM shielding, while polymer films had a low EM shielding characteristic.

Research Trends of Carbon Composite Film with Electromagnetic Interference Shielding and High Heat Dissipation (탄소 복합재 기반 전자파 차폐 및 고방열 일체형 필름 연구동향)

  • Park, Seong-Hyun;Kim, Myounghun;Kim, Kwang-Seok
    • Journal of the Microelectronics and Packaging Society
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    • v.28 no.4
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    • pp.1-10
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    • 2021
  • Recently, electronic components are becoming smaller and highly integrated. As a result, electromagnetic interference (EMI) and heat generation problems must be solved simultaneously with a small area and thickness. Graphene composites and graphite composites are lightweight materials that can simultaneously solve EMI shielding and heat dissipation problems with excellent electrical and thermal conductivity. With the recent development of synthetic technology and composite manufacturing technology, the research to application of their composites is increasing. In this paper, we reviewed the latest researches on composite films of graphene and graphite for EMI shielding and heat dissipation.

군사과학의 EMI 문제

  • 최태인
    • 전기의세계
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    • v.38 no.9
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    • pp.46-51
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    • 1989
  • TEMPEST란 통신장비나 정보처리장비에서 발산되는 미약한 전자신호가 탐지, 도청되는 현상인데 각국에서는 명칭에 대한 의미조차도 비밀로 제한하기 때문에 이 분야에 대한 정확한 기술현황 파악은 어렵다. 일반적으로 전산터미널 또는 전동타자기에서 발산되는 전자파는 단순 주파수성분을 가지며 신호의 크기도 상당히 강하므로 고감도 수신장비를 사용하면 신호를 탐지, 재생시켜 정보를 획득할 수 있다. 또한 암호장치를 사용한 통신장비의 신호도 탐지가능할 뿐 아니라 암호화되기 전의 전도성 발산신호와 안테나를 통한 복사성 발산신호를 비교하여 암호장치 자체의 알고리즘도 탐지가능하게 될 것으로 예측된다. 이와같은 전자파도청을 방지하기 위해 주요 통신 장비나 전자장비는 차폐상자를 사용하여 전자파의 복사성 발산신호를 비교하여 암호장치 자체의 알고리즘도 탐지가능하게 될 것으로 예측된다.

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Electromagnetic Environment Analysis of Goheung Aviation Center (고흥항공센터의 전기장 환경 분석)

  • Jang, Kyung-Duk;Kim, Tae-Youn;Jang, Jae-Woong;Min, Byong-Hee;Cho, In-Kyoung;Moon, Guee-Won
    • Aerospace Engineering and Technology
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    • v.12 no.1
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    • pp.46-53
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    • 2013
  • In this study, the analysis of electromagnetic environment of goheung aviation center was performed. If the test object has restrictions to be tested in indoor test facility, open area test site can be used to perform EMC test. Open area test site shall have no obstacles that can generate or reflect the electric field so as to prevent the measurement result from being influenced by unnecessary field. Goheung aviation center is surrounded by fields, and has no buildings that can reflect electric field, so the center can be a good candidate for open area test site. Ambient noise at Goheung aviation center was measured, and the result show that the center has good electromagnetic environment to perform EMC test for large volume object.

Shielding Effectiveness of Metallic Enclosure with a Rectangular Slit Aperture (직사각형 슬릿 개구를 갖는 금속 함체의 차폐 효과에 대한 연구)

  • Lee, Soong-Keun;Seong, Cheol-Min;Kim, Eun-Ha;Ryu, Seung-Real;Lee, Jae-Hyun;Park, Dong-Chul
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.23 no.5
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    • pp.652-659
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    • 2012
  • Shielding effectiveness(SE) of metallic rectangular enclosure with rectangular slit apertures at horizontal polarization (HP) and vertical polarization(VP) is investigated. The magnetic polarizability of the rectangular slit apertures and the resonance modes of the metallic rectangular enclosure are analyzed theoretically. The simulation results based on these theoretical analyses are compared with the measured ones. The dependence of the shielding effectiveness on the location of the calculation probe inside the enclosure is also investigated.