• Title/Summary/Keyword: 전파흡수체

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Development of EM Wave Absorber for Wireless LAN at 2.4 GHz (2.4 GHz 무선랜용 전파흡수체 개발)

  • Lee, Dae-Hee;Kim, Dong-Il;Choi, Chang-Mook;Che, Seung-Hun
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • v.1
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    • pp.113-118
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    • 2006
  • Recently, wireless LANs are often applied in home or office because of its various of convenience. Frequency rage of wireless LANs specified by IEEE 802.11b is at 2.4 GHz. The bluetooth, the microwave oven, and the PDA(Personal Digital Assistants) uses ,however, the same frequency band. So problems will be produced in these environments, such as multi-pass interference and system-to-system interference. These problems can be eliminated by using EM wave absorber. In this paper, we designed and fabricated EM wave absorber using Sendust, $Al(OH)_3$, and CPE. The double-layered EM wave absorber with thickness of 1.5 mm has absorption ability more than 10 dB at 2.4 GHz.

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Stealth기술의 본질-전파흡수체의 원리와 응용

  • Jo, Seong-Baek
    • Defense and Technology
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    • no.6 s.160
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    • pp.40-47
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    • 1992
  • 전파흡수체의 응용분야는 사용목적에 따라 민수용과 군수용으로 크게 대별된다 민수용으로는 통신기기의 발달로 인하여 최근에 가장 문제가 되고 있는 전자파 장애(EMI) 대책용으로 사용되며 군수용으로는 무기체계의 생존성 향상(스텔스)으로 사용된다 여기서는 군수용에 초점을 두어 대표적인 응용 예를 살펴보았다

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An Analysis of Natural Lacquer Characteristics and EM Absorber's Absorption Characteristics Using Natural Lacquer by Binder (옻의 특징과 옻을 지지재로 사용한 전자파 흡수체의 두께에 따른 흡수 특성 분석)

  • 최동한;김동일;김기만
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2004.04a
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    • pp.29-34
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    • 2004
  • Generally, a silicone rubber and a chloride polyethylene(CPE) have been used for the development of high-performance composite EM(ElectroMagnetic) wave absorbers. In this study, the EM wave absorption abilities for natural lacquer which is newly suggested in this study as a binder for composite EM wave absorbers were investigated to develop an improved EM wave absorbers. In addition, MnZn ferrite composite EM wave absorbers mixed with the natural lacquer were prepared and their absorption ability was also investigated. MnZn ferrite composite EM wave absorbers which employs the natural lacquer as a binder showed an improved EM wave absorption characteristics in comparison with the conventional binder such as a silicone rubber and a chloride polyethylene(CPE). The matching frequency and the absorption ability of EM wave absorbers mixed with natural lacquer can be controled the change of the thickness of them.

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EM Wave Absorption Properties on Particle Size and Permeability of ferrite and Preparation Temperature in Absorbers for Mobile Phones (휴대전화기용 전파흡수체에 있어 페라이트 입자크기와 투자율, 시편제작온도에 따른 전파흡수특성)

  • 김동일;옥승민;송재만;김기만;신승재;문상현
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.15 no.4
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    • pp.406-413
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    • 2004
  • In this study, we investigated the reflection coefficient of absorbers fur mobile phone on average Particle size and preparation temperature of specimens. We used recycled MnZn ferrite with initial permeability of 2,500 and 10,000 as starting materials. Absorption ability increased at 1.8 ㎓ which is frequency fur mobile phones with increasing average particle size. We developed a sheet type electromagnetic wave absorber with the thickness of 1 mm which showed reflection coefficient of -3.8 ㏈ at 1.8 ㎓.

A Study on Development of Ferrite Wave Absorber with Cutting Corn-Shaped Type (원추절단형 폐라이트 전파흡수체의 최적설계 및 제작에 관한 연구)

  • 김동일;박종구;정세모;이영구
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2000.10a
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    • pp.153-156
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    • 2000
  • The remarkable progress of electronics and radio communications technology has made our life abundant. On the other hand, the countermeasure of EMC becomes more important socially according to the increased use of electromagnetic waves. It had been required that the absorbing ability of an electromagnetic wave absorber is more than 20 dB, 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 30 MHz to 18 GHz in the bandwidth of EMI measurement. In this paper, we proposed the cutting com-shaped type satisfying the above requirments and carried out broadband design using the equivalent material constants method. Moreover, we have fabricated it and compared its characteristics with simulated one.

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A Study on the Evaluating Characteristics of EM Wave Absorber for Noise Suppression from PCB (PCB상의 노이즈 제거용 전파흡수체의 특성 평가에 관한 연구)

  • Kim, Dong-Il;Choi, Dong-Soo;Yoon, Sang-Gil;Yoo, Gun-Suk
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.20 no.6
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    • pp.509-515
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    • 2009
  • In this paper, we analyzed and evaluated noise suppression characteristic of EM wave absorber. We fabricated several absorber samples in different ratios of Sendust and Amorphous with CPE(Chlorinated Ploy-ethylene) as binder and calculated material constants by measured S-parameter. Then, we confirmed that the noise suppression characteristic of EM wave absorbers using microstrip line. A microstrip line with EM wave absorber placed on its top was used to evaluate the conduction noise suppression. As a result, noise suppression effect show different charateristic by changing relative permeability. Therefore, EM wave absorber using Sendust show excellent characteristic. In particular the maximum power absorption over 90 % in 1.7 GHz to over 6 GHz has obtained when composition of Sendust:CPE=80:20wt.%.

A Study on Development of Ferrite Wave Absorber with Cutting Corn-Shaped Type (원추절단형 페라이트 전파흡수체의 최적설계 및 제작에 관한 연구)

  • 김동일;박종구;정세모;이영구
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.4 no.4
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    • pp.721-726
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    • 2000
  • The remarkable progress of electronics and radio communications technology has made our life abundant. On the other hand, the countermeasure of EMC becomes more important socially according to the increased use of electromagnetic waves. It had been required that the absorbing ability of an electromagnetic wave absorber is mote than 20 dB, the bandwidth of which is required through 30 MHz to 1,000 MHB for satisfying the international standard about an anechoic chamber lot EMl/EMS measurement. From November of 1998, however, the CISPR11 has accepted the extended frequency band from 30 MHz to 18 GHz in the bandwidth of EMI measurement. In this paper, we proposed the cutting corn-shaped type satisfying the above requirements and carried out broadband design using the equivalent material constants method. Moreover, we have fabricated it and compared its characteristics with simulated one.

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