• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.21 no.10
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• pp.1184-1193
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• 2010

The upper frequency of international EMC regulations is being expanded above 1 GHz. Radiated emissions above 1 GHz are different from those below 1 GHz that is existing upper regulation frequency, and which have lower field strength and sharper and tilted beam-width, relatively. In this paper, an effective evaluation method to be used above 1 GHz is studied using an offset parabola antenna system having a double-ridged horn antenna as a feed. First, simple model is proposed for calculating antenna factor and field uniformity of the parabola antenna system, and then real radiated emission and radiated susceptibility measurements are performed using a constant noise emitter and the suggested antenna system. The results show that the proposed antenna system has higher gain and power efficiency, and wider field uniformity relative to a conventional double-ridged horn antenna. Therefore, it is confirmed that the proposed system can be effectively used for EMC measurements above 1 GHz.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2005.11a
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• pp.409-414
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• 2005

This study is based on the recent CISPR(International Special Committee on Radio Interference) research which is focused on the Radiated Emission test method above 1 GHz and explained "w"(Measurements dimension) for the antenna's $\theta_{3dB}$ characteristic. And expound the work in progress in the IEC Standard for the measurement methods and the limits above 1 GHz.

• Proceedings of the IEEK Conference
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• 2006.06a
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• pp.65-66
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• 2006

In this paper, we designed and fabricated a broadband antenna for EMI site validation above 1 GHz. To develop the antenna which is satisfied omni-directional radiation pattern and broadband characteristics required by CISPR, we designed biconical type with cylindrical load. The developed antenna has good characteristics of the radiation patterns and VSWR<2 the frequency range from 1 GHz to 18 GHz.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.22 no.3
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• pp.336-344
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• 2011

The purpose of this study is to analyze the radiation-pattern characteristics above 1 GHz for the electromagnetic wave radiated from multi-slot such as ventilations, etc. on the enclosure of an EUT and so to make recommendations for suitable test methods. An experimental EUT was formed by putting a comb-generator at the center of a rectangular enclosure with 4 slots, and its radiation pattern was analyzed in the frequency range of 1~6 GHz. As analysis results, multi-lobe appears above 2 GHz and the number of multi-lobes is growing as the frequency increases. And real radiated-emission measurements were performed for the experimental EUT by scanning a receiving antenna in the height of 1~4 m and tilting toward maximum radiation, as well as setting the height of a receiving antenna to the central position of the EUT which is prescribed at the present standards. The measured results are +12.8 dB in the scanning and +16.4 in the scanning and tilting compared with the present standard test method. Therefore, the latter must be revised in order to consider the radiation pattern above 1 GHz.

• Publications of The Korean Astronomical Society
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• v.15 no.1
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• pp.61-86
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• 2000

Radio astronomy, on its part, requires 'quiet zones' to be able to receive incoming cosmic signals unaffected by interference to enable astronomers and others learn about universe. The agenda item 1.16 of WRC-2000 contains a number of issues relevant for radio astronomy, but some of them are more important than others. The preparations for WRC-2000 have reached a close-to-final stages, with a number of proposals to this agenda item submitted to the ITU by many countries and groups of countries, like APT, CEPT and CITEL. There is no clear preference to anyone of these proposals since their differences are only minor. However, several points remain to be solved in the APT and CITEL. Fortunately, the preparation went very well, and consensus was reached on allocations above 71 GHz and three resolutions. The radio astronomy has obtained about 100 GHz of new spectrum allocations in bands above 71 GHz. In addition, a new resolution was approved by plenary meeting of WRC-2000. It deals with the consideration by a future WRC of sharing and compatibility issues between passive and active services in adjacent bands particularly with the space services (downlinks) into radio astronomy above 71 GHz. Therefore, in future, there should be a need for studies to be made to determine if and under what conditions sharing is possible, given that modifications were made on the basis of requirements known now and that little was known of requirements and implementation plans for active services in bands above 71 GHz.

• Journal of electromagnetic engineering and science
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• v.8 no.1
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• pp.1-5
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• 2008

In this paper, a biconical type antenna is proposed for EMI test site validation above 1 GHz. To achieve broadband and omni-directional radiation patterns required by international standard(CISPR), the proposed antenna consists of general bicones with cylindrical loads and adopts side feeding method to minimize the influence on H-plane pattern due to feeding cable, balun, and connector. The radiation patterns of the fabricated antenna are measured and the results are compared with CISPR criteria and commercial antenna in our interest frequencies. Although the proposed antenna has a few problems in frequency range of 1 GHz to 2 GHz, it has relatively better performance than commercial antenna.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.17 no.9 s.112
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• pp.874-882
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• 2006

We surveyed the international and national spectrum & technical standardization trends of extremely adaptive frequency bands $57\sim64GHz$ that can provide 1 Gbps bit-rate ultra broadband service in above 30 GHz millimeter waves, and analyzed service scenarios and the characteristics of these bands, As a result of these analysises, 1 Gbps ASK channel bandwidth needs 2.5 GHz and total bandwidth calculated 7 GHz for dual FDD. finally, we proposed the nationally suitable allocation plan of millimeter wave bands $57\sim64GHz$.

• Journal of electromagnetic engineering and science
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• v.11 no.4
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• pp.304-310
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• 2011

The application of time-domain methods in emission measurement instruments allows for a reduction in scan time by several orders of magnitude and for new evaluation methods to be realized such as the real-time spectrogram to characterize transient emissions. In this paper two novel systems for time-domain EMI measurements above 1 GHz are presented. The first system combines ultra-fast analog-to-digital-conversion and real-time digital signal processing on a field-programmable-gate-array (FPGA) with ultra-broadband multi-stage down-conversion to enable measurements in the range from 10 Hz to 26 GHz with high sensitivity and full-compliance with the requirements of CISPR 16-1-1. The required IF bandwidths were added to allow for measurements according to MIL-461F and DO-160F. The second system realizes a system of time-interleaved analog-to-digital converters (ADCs) and has an upper bandwidth limit of 4 GHz. With the implementation of an automatic mismatch calibration, the system fulfills CISPR 16-1-1 dynamic range requirements. Measurements of the radiated emissions of electronic consumer devices and household appliances like the non-stationary emissions of a microwave oven are presented. A measurement of a personal computer's conducted emissions on a power supply line according to DO-160F is given.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2012.05a
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• pp.821-822
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• 2012

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2007.10a
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• pp.849-852
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• 2007

In this paper, the high gain and the broadband microstrip patch antenna, which is applicable to 5 GHz band wireless LAN, is designed in order to integrate IEEE 802.11a's detailed standards($a:5.15{\sim}5.25$, $b:5.25{\sim}5.35$, $c:5.725{\sim}5.875$ [GHz]). Designed patch antenna has settled resonance frequency by insert substance(polyurethane: ${\varepsilon}_r=6.5$) between the separated parasitic patch and radiation patch for the purpose of miniaturize. And the form (${\varepsilon}_r=1.03$) were to fix the separated radiation patch and ground plans by air. Designed frequency bandwidth(VSWR 2:1) of the antenna showed broadband characteristic of $4.9[GHz]{\sim}6.1[GHz]$ to about 1.2[GHz]. Also the E-plan and H-plan profit 12[dBi] above, the 3[dB] beamwidth showed the characteristic over the E-plan $30^{\circ}$ and H-plan $60^{\circ}$ to be improved.