• Title/Summary/Keyword: radiated electromagnetic waves

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A Study on Analysis of Target Characteristics Using Electromagnetic Waves (전자파를 이용한 목표물의 특성 분석에 관한 연구)

  • Lee, Jonggil
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.19 no.6
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    • pp.1289-1295
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    • 2015
  • Electromagnetic wave signals radiated from an antenna are reflected by targets and received through the same antenna. These received signals show different characteristics according to various target materials having different dielectric constants. Therefore, target characteristics can be recognized if we can utilize these return signals efficiently. this method can be applied for discrimination and classification of hazardous materials. In this paper, utilizing these experimentally obtained signals, correlation characteristics are obtained and analyzed for classification and discrimination purposes. Although the correlation method requires the storage of reference signals, it shows very promising results. this correlation method can be applied for classification and discrimination of hazardous materials.

A Study on Characteristics of SAR Distribution in the Human Head for Portable Phone (휴대폰 전파에 의한 인체두부의 SAR 분포특성에 관한 연구)

  • 김경환;민용기김정
    • Proceedings of the IEEK Conference
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    • 1998.10a
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    • pp.355-358
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    • 1998
  • This paper investigate the interaction of electromagnetic fields(EF's) in the human head with respect to the radiated waves from 1.8〔GHz〕 PCS terminal that the titled angles of a monopole antenna between the head and the horizontal axis of the terminal are 45, 60, 75 and 90 degrees respectively. And then, it is found the fact that the induced SAR distri bution in the model of the head gradually decreases by in creasing the titled angle.

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A Study on Electromagnetic Radiation of Neon Sign by ON/OFF (점멸에 의한 네온사인의 방사전자파 특성에 관한 연구)

  • 김인식;이동인;이광식
    • The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.9 no.6
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    • pp.23-31
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    • 1995
  • As a study on electromagnetic radiation emission from the neon signs, this paper has investigated the characteristics of frequency bands and spectra intensities under the operations of the sign's OFF, ON/OFF and continuous ON states. Also we have studied the above characteristics when a distance between the sign and the antenna is varied. All data were obtained in the range of 0.1∼1,000[MHz] by using spectrum analyzer along with the loop, biconical and log periodic antenna. As the result, we found that the radiated electromagnetic waves of the sign at continuous ON states were measured only in the range of 30∼400[MHz] but those of the sign at ON/OFF states were appeared widely in the range of 2∼1,000[MHz].

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Characteristics of Radiated Electromagntic Wave Caused by Progress of Partial Discharge in Power XLPE(Crosslinkable Polyethylene) Dielectric (전력용 XLPE 절연체의 부분방전진전에 따른 방사전자파 특성)

  • Lee, H.C.;Park, K.S.;Yoon, D.H.;Lee, S.H.;Kim, J.H.;Kim, K.Ch.;Lee, K.S.
    • Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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    • 2004.05a
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    • pp.304-307
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    • 2004
  • This paper simulated partial discharge caused by 22.9[kV] power cable using XLPE(Peroxide Crosslinkable Polyethylene) insulation having the outside damage. As one of the insulation diagnostic method a radiated electromagnetic waves were measured by an UHF method using a BiconiLog antenna(EMCO-3142) and a spectrum analyzer used to measure EMI, EMC. From results of this study, It was confirmed that discharge progress were possible to be estimated by the proposed method.

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The Measurment and Analysis of Electromagnetic Waves by Discharge in Air (기중방전에 대한 방사전자파 측정과 분석)

  • Lee, Sang-Hoon;Park, Kwang-Seo;Kim, Chung-Nyen;Kim, Ki-Chai;Lee, Kwang-Sik;Lee, Dong-In
    • Proceedings of the KIEE Conference
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    • 1999.07e
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    • pp.2028-2030
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    • 1999
  • In this paper, partial discharge(PD) was generated under the two types of needle -plane electrodes in the air. Using a monopole antenna to detect the radiated electromagnetic waves by stream of charge between the electrodes. the progress of partial discharge was studied. To analyze the progress of PD, statistical re-search was introduced. It was executed by personal computer and it can be possible to visualize the progress of PD. The t-test was used for lower voltage applied. The population of background noise spectrum and applied voltage spectrum showed the difference. The new method was introduced to analyze the spectrum. According tho the magnitude of applied voltage, the different statistical methods were used. The results obtained from this work will provide the useful information on partial discharge in time to come.

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The Fundamental Study About Partial Discharge Detection With The Radiated Electromagnetic Wave Characteristics (방사전자파 특성을 이용한 부분방전 검출의 기초연구)

  • Lee, Sang-Hun;Park, Gwang-Seo;Kim, Chung-Nyeon;Lee, Hyeon-Dong;Song, Hyeon-Jik;Kim, Gi-Chae;Lee, Gwang-Sik;Lee, Dong-In
    • The Transactions of the Korean Institute of Electrical Engineers C
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    • v.49 no.7
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    • pp.412-417
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    • 2000
  • This paper offer fundamental materials about Partial Discharge(PD) detection by electromagnetic waves. All spectrum data-usually used as grape- can be used as numbers. And then the average of background noise spectrum strength was made. Average value subtract from every data. Then average value appeared, graphed. The graph was compared with the magnitude of charge. The shape of changes is similar, and the change of electric field strength could be seen in one sight. When the magnitude of charge is over than 100[pC], antenna can detect partial discharge. So this method will be very useful to diagnosis of insulation. It the performance of the antenna used in this experiment is analyzed, good results can be obtained.

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Detection of Partial Discharges by a Monopole Antenna in Insulation Oil (모노폴 안테나를 이용한 유중 부분방전의 검출)

  • Park, Dae-Won;Lee, Jung-Yoon;Kil, Gyung-Suk
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.25 no.9
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    • pp.727-731
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    • 2012
  • This paper dealt with the measurement and analysis of electromagnetic waves radiated from a partial discharge (PD) source in insulation oil to apply condition monitoring of oil-immersed transformers. Two types of narrow-band monopole antennas with the resonant frequency of a 500 MHz and a 1 GHz were designed and fabricated. Also, a needle-plane electrode system was manufactured to simulate PDs and the curvature radius of the needle is 10 ${\mu}m$ and the diameter of the plane is 60 mm. Electromagnetic wave was measured by the PD measurement system with the monopole antennas. Detection sensitivity of the fabricated antenna was compared for the same PD magnitude; 620 $mV_{peak}$ for the 500 MHz antenna and 960 $mV_{peak}$ for the 1 GHz antenna to the PD magnitude of 74 pC. Consequently, the 1 GHz monopole antenna is more effective to detect PDs in oil-immersed transformers.

A Characteristics of RF Sensitivity for a Firing Fuse (기폭용 퓨즈의 RF 감도 특성)

  • 간종만;권준혁
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.15 no.6
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    • pp.573-578
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    • 2004
  • EED consists of bridgewire, explosive charge, lead pins and metal case. If a firing signal is injected to EED, the explosive charge in EED is initiated by heating of bridgewire. Electromagnetic waves radiated from high power transmitters or radars can also cause unexpected firing of EED. Therefore, EMC design and test requirements for EED in military specifications are established and applied. This report describes the characteristics of RF sensitivity fur a firing fuse which is used fur EMC test instead of a real EED installed in aircraft. RF firing level of the fuse was predicted using transmission line(TL) theory. n sensitivity and RF sensitivity specified in military specifications were measured.

Insulation Diagnosis Study of Power XLPE Cable by Used Atenna (안테나를 이용한 전력용 케이블의 절연진단 연구)

  • Lee, H.C.;Choie, U.H.;Park, K.S.;Yoon, D.H.;Jee, S.W.;Lee, S.H.;Kim, C.N.;Lee, K.S.
    • Proceedings of the KIEE Conference
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    • 2004.07c
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    • pp.1805-1807
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    • 2004
  • This simulated partial discharge caused by 22.9[kV] power cable using XLPE(Peroxide Crosslinkable Polyethylene) insulation having the outside damage. Asone of the insulation diagnostic method a radiated electromagnetic waves were measured by an UHF method using a BiconiLog antenna(EMCO-3142) and a spectrum analyzer used to measure EMl, EMC. From results of this study, It was confirmed that discharge progress were possible to be estimated by the proposed method.

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Cable Effect Analysis Inside an Electrically Large Structure from an External Electromagnetic Waves (전자파에 의한 대형구조물 내부 케이블 영향 해석)

  • Lee, Jae-Min;Yoon, Seong-Sik;Lee, Jae-Wook;Han, Jung-Hoon
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.28 no.2
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    • pp.155-158
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    • 2017
  • With the help of technical development in the electronic industries, the electronic devices employing the cutting-edged technology are spread in all the area requiring electromagnetic communications. Especially, because of the presence of electronic devices in a variety of research fields like automotive vehicle, train, and aircraft, the research area such as the malfunction and critical damage of the internal system and microwave devices due to the unexpected radiated high-powered EM effects are very important even for the possible occurrence of human damage. In this paper, the effects of electromagnetic fields into the cable connecting the electronic devices and many sensors inside the target structure is treated because of potential malfunction or hardware disorders. In addition, correlation function and transmission line theory have been employed for the analysis of the induced current on the cable inside an electrically large resonant structure.