• 제목/요약/키워드: wave absorber

검색결과 253건 처리시간 0.019초

Ni-Mn-Zn Spinel Ferrite-Rubber Composite의 전파흡수특성에 관한 연구 (A Study on Electromagnetic Wave Absorbing Properties of Ni-Mn-Zn Spinel Ferrite-Rubber Composite)

  • 박연준;김동일
    • 한국항해학회지
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    • 제23권1호
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    • pp.15-22
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    • 1999
  • In this paper, ferrite-rubber composite has been studied in order to apply to RF-A-PF in a super wideband electromagnetic absorber in RF-A-PF type, which can be used for a general purpose anechoic chamber. $Ni_x - Mn_0.1 - Zn_{(1-x-0.1)}ㆍFe_2O_4$ ferrite powder has been fabricated, then, using this, 〔$Ni_x - Mn_0.1 - Zn_{(1-x-0.1)}ㆍFe_2O_4$〕-Rubber composite for RF-layer in the RF-A-PF type absorber has been fabricated and it's characteristics have been analyzed. As a result, it has been clearly shown that the 〔$Ni_x - Mn_0.1 - Zn_{(1-x-0.1)}ㆍFe_2O_4$〕-Rubber composite has excellent electromagnetic wave absorbing properties.

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30 MHz~1000 MHz 고주파 대역에서 Ni-Zn 계 페라이트의 소결조건에 따른 전파흡수 특성 (Effects of Sintering Schedule of Ni-Zn Ferrites on Properties of Electromagnetic Wave Absorber between 30 MHz and 1000 MHz)

  • 김경용;김왕섭;주윤돈
    • 한국세라믹학회지
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    • 제28권8호
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    • pp.640-646
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    • 1991
  • Recently intensive studies have been focussed on ferrites which have high magnetic loss because of the increasing need for the prevention of EMI (Electromagnetic Interference). We investigated effects of microstructures of Ni-Zn ferrites on magnetic losses, magnetic properties, and behaviors of electromagnetic wave absorbers. The characteristics of the absorber were influenced by the sintering conditions. A Ni-Zn ferrite with the thickness of 7$^{\circ}C$/min and the cooling rate of 7$^{\circ}C$/min. It satisfied the absorbing properties in the wide frequency ranges including VHF (90∼220 MHz), UHF (470∼770 MHz)

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복합형 등방성 Ferrite-Rubber Composite의 전자파 흡수특성에 관한 연구 (A Study on Electromagnetic Wave Absorbing Properties of Complex Isotropic Ferrite-Rubber Composite)

  • 김동일;박연준;김하근;사공건
    • 한국정보통신학회논문지
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    • 제3권1호
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    • pp.35-42
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    • 1999
  • This paper describes the characteristics of the complex isotropic ferrite-rubber composite for a super wideband electromagnetic absorber in RP-A-PF type, which can be used for an anechoic chamber, wall material to prevent TV ghost, etc. The $Ni_x-A_{0.1}-ZN_{(1-x0.1)}$. $Fe{_2}O_4$ ferrite powder has been fabricated. Using this, then, [$Ni_x-A_{0.1}-ZN_{(1-x0.1)}$. $Fe{_2}O_4$]-Rubber composite for RF-layer in the RF-A-PF type absorber has been fabricated and it's characteristics has been analyzed. As a result, it has been shown that the [$Ni_x-A_{0.1}-ZN_{(1-x0.1)}$. $Fe{_2}O_4$].Rubber composite has excellent electromagnetic wave absorbing properties.

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콘테이너선의 파랑중 내항성 연구 (Seakeeping Study of a Container Ship in Regular Waves)

  • 양승일;홍석원;이상무
    • 한국기계연구소 소보
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    • 통권9호
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    • pp.193-208
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    • 1982
  • Flap type wave-maker, wave absorber, motion measuring equipment and related instruments were newly installed at Ship Experimental Towing Tank, Ship Research Station, KIMM. The model tests in regular head and following waves were successfully carried out and the motion and wave loads in regular and long crested irregular waves were calculated for a container ship model which was adopted as the hull form for the comparative calculations of the ITTC Seakeeping Committee. The results of model tests show good agreement with calculated results and the latter are generally in good agreement with the results of the comparative calculations.

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Sheet형 전파흡수체에 있어 페라이트 입자 크기의 제어에 따른 전파흡수특성 (Electromagnetic Wave Absorption Properties According to by Controling Ferrite Particle Size in Electromagnetic Wave Absorber of Sheet Type)

  • 김동일;김수정;옥승민;송재만
    • 한국전자파학회:학술대회논문집
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    • 한국전자파학회 2002년도 종합학술발표회 논문집 Vol.12 No.1
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    • pp.319-323
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    • 2002
  • Electromagnetic wave absorbers with the shape of sheet have been fabricated and their absorption properties are measured. The fabricated ferrite absorbers have different particle sizes and the absorbtion property is increased with decreasing the size of particle in a certain frequency range of 2.4∼3.2 ㎓.

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X-Band Radar용 도료형 전파흡수체의 실장실험 (Far Feild test on Electromagnetic Wave Absorber in Paint Type for X-babd Radar)

  • 안영섭;김동일;정세모
    • 한국전자파학회지:전자파기술
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    • 제4권3호
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    • pp.3-10
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    • 1993
  • 전파흡수체의 전파흡수능 측정방법은 기본적으로 다양한 마이크로파 측정법이 이용될 수 있지만, 레이다용 전파흡수체의 경우, 전파의 주파수가 높기 때문에 파장이 짧아서 측정오차가 큰 문제점이 있다. 따라서, 지금까지는 $20mm\Phi$동축관 및 구형도파관을 이용한 재료정수측정법과 전파흡수능측정기법에 관하여 검토하여 왔다. 본 논문에서는 그동안 실험실적으로 설계하여 온 X-Barn Radar용 전파홉수체를 실용의 상태에 가까운 반사 전력법에 의하여 그 성능을 예비평가하고, 실제의 target를 제작하여 X-Band Radar로 실장실험한 결과에 관하여 보고한다.

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