• Journal of Advanced Navigation Technology
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• v.7 no.2
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• pp.101-107
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• 2003

In this study, we provide a single element log-periodic antenna that the feeding networks and array structures are aperture coupled and series dipole array type. We made the antenna for direct receiving the Moogoongwha satellite broadcasting signal. The transmission power was able to feed the patch dipole in series due to lay perpendicularly 8 series patch dipole on tapered slot. The patch dipole radiation pattern which fed in series power, make the main beam direction up $37^{\circ}{\sim}42^{\circ}$ within the BS/CS bandwidth. The main beam gain was measured 9.31~11.03 dBi. Using 32 elements to array the elements properly, we acquire $4{\times}8$ array structure on limited PCB board. As a result, it has been found that the new planar DBS antenna structure have high gain over 10dBi and acceptable elevation angle over 42 degree, and we can apply this result to commercial DBS reception antenna manufacturing.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.41 no.11
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• pp.891-899
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• 2013

This paper suggests a test and evaluation procedure of conformal load-bearing antenna structure(CLAS) for high speed military jet application. A log periodic patch type antenna was designed for multi-band communication and navigation antenna. Carbon/Glass fiber reinforced polymer was used as a structure supporting aerodynamic loads and honeycomb layer was used to improve antenna performance. Multi-layers were stacked and cured in a hot temperature oven. Gain, VSWR and polarization pattern of CLAS were measured using anechoic chamber within 0.15~2.0 GHz frequency range. Tension, shear, fatigue and impact load test were performed to evaluate structural strength of CLAS. Antenna performance test after every structural strength test was conducted to check the effect of structural test to antenna performance. After the application of new test and evaluation procedure to validate a new CLAS, a design improvement was found.

• Journal of the Korean Institute of Telematics and Electronics
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• v.20 no.3
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• pp.40-44
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• 1983

A wide band quasi-log periodic microstrip antenna is designed using circular-disc microstrip patches as a basic radiator. The radiating elements are series-fed by a coplanar feeding network which consists of an open circuited feed line with a branch line connected to each radiating element. Experiment results show that the values of VSWR are less than 2.3 over the range of 2.72-3.43 GHz.

• Proceedings of the KIEE Conference
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• 2003.10a
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• pp.207-210
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• 2003

가스절연개폐장치(Gas-Insulated Switchgear, GIS) 내부에서 발생하는 부분방전(Partial Discharge, PD) 신호는 1ns이하의 상승시간(rising time)을 가지므로, 이 신호를 효과적으로 측정하기 위해서는 초광대역(Ultra Wide Band, UWB)특성을 갖는 커플러가 필요하다. 본 논문에서는 이러한 UWB 특성을 구현하기 위해, 대수주기 톱니형 평면 안테나(log-periodic toothed planar antenna)와 등각 스파이럴 패치안테나(equi-angular spiral patch antenna)형태의 두 가지 초광대역 UHF 커플러를 설계 제작하였다. 제작한 커플러들의 특성을 파악하기 위해 안테나의 급전부에, 자체 설계한 매칭 회로인 발룬(balun, balance to unbalance)을 장착하여, 반사계수, 모의펄스에 의한 검출신호, 스펙트럼 둥을 측정하였다.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.7 no.3
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• pp.142-146
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• 2014

In this paper, an antenna which has quad band in GSM/DCS/PCS/Bluetooth is proposed. This structure is designed with miniaturization for wide band characteristic based on monopole antenna and log-periodic toothed trapezoid patch antenna which has slots. To achieve multi-bandwidth is used the microstrip line on the substrate. An antenna size is $35mm{\times}20mm$ on FR-4(${\varepsilon}r=4.4$) ground substrate of $35mm{\times}75mm{\times}1mm$ size. And proposed antenna is satisfied with impedance bandwidth(VSWR ${\leq}$ 3). The simulated maximum radiation gain is 1.92 dBi, 3.26 dBi, 3.97 dBi at the center frequency of 0.92 GHz, 1.97 GHz, 2.45 GHz, respectively.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.42 no.7
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• pp.567-575
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• 2014

This paper suggests an installation procedure of a smart skin prototype into an aircraft, flight demonstration test procedures and test results. Four communication and navigation antennas are embedded into one Conformal Load-bearing Antenna Structure(CLAS). Log periodic patch type antenna was designed as a multi-band antenna to cover four antenna frequency bands. The requirements of CLAS were verified by ground tests before aircraft installation. A CLAS speed-brake was installed into KT-1 aircraft and performances of dual antennas were verified as multi-antenna tests on the ground. Electromagnetic compatibility tests were conducted to check compatibility between the CLAS and all existing equipments. Flight demonstration tests were conducted by one sortie of flight test for one antenna. The activeness and continuity of communication and navigation signal during the flight, null area of antenna signal along the circling flight were monitored. The embedded antennas worked better than expected during four sorties of flight tests.

• Proceedings of the KIEE Conference
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• 2004.07c
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• pp.1769-1771
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• 2004

가스절연 개폐장치(GIS)용 극초단파 부분 방전 측정장치에 다양하게 사용 할 수 있는 외장형 부분 방전 (PD) 센서를 제작하였다. Fat-dipole, 대수주기(log-periodic), spiral 및 log-spiral 형 패치안테나를 이용한 외장형 PD 센서의 주파수 특성과 검출감도를 기본 Dipole형 센서와 비교하였다. 제작된 센서는 170kV 단상 GIS의 스페이서에 장착하여 5 pC PD에 대한 각 센서의 주파수 특성과 감도를 측정 하였다.

• Proceedings of the KIEE Conference
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• 2008.10a
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• pp.83-84
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• 2008

인구의 증가로 인한 전력수요의 증가는 가공 및 지중 송진설비의 대용량화로 이어져왔다. 그러나 최근 도시 경관과 전자파로 인한 건강 등에 대한 관심이 급증하면서 주거지 주변 송전선로 실리에 대한 민원이 증가하고 있다 을에 대한 대안으로 대용량 전력송전이 가능하고 가공 및 지중송전의 단점을 보완한 가스결연 송전선로(Gas Insulated Transmission Line, GIL)가 개발되었다. 선진국에서는 가스 절연으로 우수한 절연성능과 안정성을 가지며, 기존 교통용 터널 또는 지하 전력구에 설치함으로써 주변 경관을 해치지 않고 낮은 전계 형성 등의 장점을 가진 가스절연송전선로의 연구와 개발에 많은 노력 기울이고 있다[$1{\sim}5$]. 본 논문에서는 전력기기들의 결함진단에 많이 사용되는 부분방전 측정을 가스절연 송전선로에 적용할 수 있는 최적의 측정용 센서를 개발하여 유사한 구조를 가지는 75kV GIS Mock-up과 Free moving particle 모의 방전 셀을 이용하여 발생시킨 부분방전 신호를 측정하여, 광대역 특성을 보이는 대수주기 패치 안테나와의 성능을 비교하였다.