• Title/Summary/Keyword: Sheilding effectiveness

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The Evaluation of the Characteristics of Electromagnetic Waves on CFRTP for Multimedia Instrument Applications (Multimedia 기기에의 적용을 위한 CFRTP에 대한 전자파 특성의 평가)

  • ;Ri-ichi Murakami
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.8 no.3
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    • pp.254-263
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    • 1997
  • As the communication and electronic industry develops, it is important to study the electromagnetic shielding effectiveness (SE) of carbon fiber (CF) reinforced thermal plastics (CFRTP) against the electromagnetic (EM) radiation. In this paper the shielding effectiveness of CFRTP was measured experimentally in an electromagnetic shielding room. The resin ma- terials used were PC, PP, PEI, PMMA and PA. Experiments were carried out by using a copper box and a monopole antenna with a spectrum analyzer. From the experimental results it was found that CF was a good candidate as an electromagnetic shielding material. The sheilding effectiveness was found to be increased in the composite as the number of laminated layers of CF was increased. As the minor damage increased, the SE increased due to increasing of the plane density, transmitting thickness and reflected angle of the CF. Other characteristics of the SE depended on the material used for the resin matrix, distance of the antennas and the noise frequency band.

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Design Guideline of Waveguide-Below-Cutoff Array for Electromagnetic Pulse Shielding (EMP 차폐 도파관의 형상 결정 가이드라인 작성)

  • Pang, Seung-Ki;Kim, Jae-Hun;Yook, Jong-Gwan;Kim, Yuna;Kim, Sangin
    • Journal of Energy Engineering
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    • v.25 no.1
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    • pp.86-91
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    • 2016
  • Convenient design guideline for Waveguide-below-cutoff (WBC) array is proposed to obtain the minimum waveguide length for electromagnetic pulse (EMP) shielding. The analysis includes circular, rectangular, and hexagonal WBC, determine the total length of the waveguide. When the unit side of rectangular WBC and the diagonal line of hexagonal WBC are given as 30 mm, the length of hexagonal WBC is 5 mm shorter than rectangular case with shielding effectiveness (SE) 80 dB. The length difference is deepened with SE of 100 dB, which shows approximately 30 mm shorter length for hexagonal case than others. In addition, hexagonal WBC requires much shorter length than circular WBC. In conclusion, hexagonal case is the most effective with respect to flow velocity and pressure loss for equivalent SE.