• Journal of electromagnetic engineering and science
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• 제18권3호
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• pp.169-174
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• 2018

In this paper, we propose an estimation method using multiple in-phase and quadrature (IQ) signals of different frequencies to evaluate the sample-time errors in the sampling oscilloscope. The estimator is implemented by ODRPACK, and a novel iteration scheme is applied to achieve fast convergence without any prior information. Monte-Carlo simulation is conducted to confirm the proposed method. It clearly shows that the multiple IQ approach achieves more accurate results compared to the conventional method. Finally, the criteria for the frequency selection and the signal capture time are investigated.

• 한국전자파학회논문지
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• 제24권1호
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• pp.47-54
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• 2013

본 연구는 국내 최초로 개발된 직접 비교법을 이용한 W-band 밀리미터파 전력 표준 전달 시스템에 대한 것이다. 이 시스템은 75~110 GHz 대역에서 W-band 도파관형 전력감지기의 실효 효율과 교정 인자를 측정하기 위하여 개발되었다. 전력 표준 전달 시스템 구성의 핵심 요소인 방향성 결합기의 반사 특성 평가 기법을 소개하고 실험 결과를 보인다. 구현된 시스템을 이용하여 측정하고자 하는 전력감지기의 교정 인자 측정 결과를 보이고, 불확도 요인에 대하여 고찰한다. 측정 결과를 기준값과 비교하여 W-band 밀리미터파 전력 표준 전달 시스템에 의한 측정의 유효성을 검증한다.

• Journal of electromagnetic engineering and science
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• 제18권2호
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• pp.88-93
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• 2018

Radio frequency (RF) and microwave power is one of the key quantities in the framework of electromagnetic measurement standards. Therefore, the stability of the power standard is essential to users' reliable measurements in various areas. Coaxial and waveguide thermistor mounts are used as transfer standards of RF and microwave power. Over decades, the effective efficiencies of thermistor mounts have been measured using coaxial and waveguide microcalorimeters in the frequency range of 10 MHz-40 GHz. The measurement uncertainty of the effective efficiency is evaluated. Results show that the power standards have been well maintained within the measurement uncertainty.

• 자동차안전학회지
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• 제13권2호
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• pp.7-14
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• 2021

Recently, the amount of electrical and electronic systems is increasing rapidly with the development of advanced vehicles such as ADAS, smart cars, connected cars, automated driving systems. It is necessary to examine the electromagnetic compatibility of vehicles equipped with those systems. The standards and regulations for examination of electromagnetic compatibility have been established and revised according to newly introduced electrical and electronic systems. They are administered in some different international standard associations such as ISO, CISPR, UN/ECE and are somewhat complex and bulky. In the study, the improvements and changes in them are tracked and analyzed chronologically. Research of the history of them will be helpful for understanding progress and forecasting the direction of development.

• 한국전자파학회논문지
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• 제25권4호
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• pp.426-433
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• 2014

고고도 핵폭발로 인해 고고도 전자기 펄스(HEMP)가 발생한다. 본 논문에서는 Bell 연구소와 IEC 61000-2-9 기준에 제시된 HEMP 파형이 해군 함정의 복사성 결합 통로와 전도성 결합 통로를 통해 입사할 때 침투하는 침투 전계 특성을 비교 검토하였다. 또한, 두 가지 종류의 결합에 대한 효과를 분석하고, 방호 대책을 제시하였다. 시뮬레이션 결과, IEC 61000-2-9 기준이 Bell 연구소의 기준보다 저주파수 대역을 제외하고 침투전계가 크므로 좀 더 엄격한 기준으로 볼 수 있고, 따라서 IEC 61000-2-9의 기준을 해군내 HEMP 기준으로 제시하였다. 최종적으로 HEMP 방호 대책으로 차폐 코팅, 허니컴 통풍구, TVS 소자 등을 이용하여 미국방부 기준에 부합하는 것을 확인하였다.

• 전자통신동향분석
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• 제34권3호
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• pp.86-92
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• 2019

New products and services, such as 5G and wireless power transmission equipment, have recently brought about changes in the field of electromagnetic technology. There is a need for the evaluation and measurement of the health effects of such technology. To address this need, the development of international standards related to human exposure to electromagnetic waves of these new technologies are currently being discussed. This article briefly introduces the International Standard Organization standards for human exposure to electromagnetic waves, and focuses on the major standard trends for SAR measurement techniques that employ vector probes, wireless power transfer, and 5G base station measurement.

• Journal of electromagnetic engineering and science
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• 제15권4호
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• pp.224-231
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• 2015

A comparison of the antenna parameters for R-band (1.7-2.6 GHz) and S-band (2.6-3.95 GHz) standard gain horn antennas has been performed by the Korea Research Institute of Standards and Science (KRISS), together with seven domestic participants from private companies and public institutions. Its purpose, as a proficiency test program of the 'Antenna Measurement Club' of KRISS, was to check equivalences in antenna parameter measurements between KRISS and the participants, particularly in the R-/S-band, to support antenna manufacturers and end users in Korea. The measurement parameters of this comparison are the power gain, radiation pattern, and reflection coefficient of the traveling standards for R-/S-band pyramidal standard gain horn antennas. The comparison used a gain comparison method and an extrapolation method to measure the power gain of the two traveling standards; the radiation patterns were measured in the far-field region of the transmitting and receiving antennas.

• Journal of electromagnetic engineering and science
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• 제12권1호
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• pp.63-69
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• 2012

This paper presents the design of a calculable standard dipole antenna with a hybrid balun in the frequency range of 1 GHz to 3 GHz. A new formula of the antenna factor for a dipole antenna with a hybrid balun is derived using the power mismatch-loss concept. The antenna factors derived in this paper are in good agreement with the results calculated from S-parameters. The design results show that the calculable dipole antenna with a hybrid balun can be characterized by power mismatch-loss component factors.

• 자동차안전학회지
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• 제11권1호
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• pp.17-22
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• 2019

Nowadays many two-wheeled motorcycles are used in leisure and express delivery industries. But studies of the electromagentic compatibility on motorcycles have seldom been performed and published. This paper has studied the electromagnetic safety of motorcycles considering international and domestic regulations and standards. Also, a series of experiments have been performed to evaluate the level of electromagnetic compatibility of commercially available motorcycles. As a result, detailed experimental procedures are proposed to secure the electromagnetic safety and can be used to confirm or revise the Korea Motor Vehicle Safety Standards.

• 한국전자파학회지:전자파기술
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• 제18권1호
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• pp.87-98
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• 2007