• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2006년도 하계종합학술대회
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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.

• 전기의세계
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• 제14권1호
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• pp.26-34
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• 1965

The radiation patterns and impedance of the half wave solt on the wide side of rectangular wave guide are analyzed. The measuring methods and procedures are described. And that the experimental data of the pattern and impedance of the slot are presented which are consistent with the theoretical values. The causes of error are also considered and are believed to be tolerable for the pattern and input impedance measurements. The usefulness of the slot antenna tested are also described.

• 한국전자통신학회논문지
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• 제8권9호
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• pp.1285-1291
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• 2013

본 논문에서는 광대역 특성을 갖는 이중 원형 링 모노폴 안테나를 설계 및 제작 하였다. 제안된 안테나는 평면형 모노폴 형태를 기본으로 이중 원형 링과 접지면으로 구성되어 있으며 광대역 특성을 갖도록 설계하였다. 최적화된 파라메타을 얻기 위해 상용 툴(HFSS)을 사용하여 시뮬레이션 하였으며 안테나 성능에 민감하게 적용받는 파라메타를 찾아내서 최적화된 수치를 얻었다. 얻어진 최적화된 수치를 사용하여 제안된 안테나를 제작하였다. 제작된 안테나는 광대역 특성을 갖는 대역에서 반사손실, 이득, 방사패턴의 특성을 측정하였다. 측정결과, -10dB을 기준으로 4,530 MHz(2,510-7,040 MHz)의 광대역 특성을 얻었으며 주어진 이득은 최대이득 0.71~3.38 dBi 그리고 평균이득 -3.85~0.3 dBi을 얻었다. 측정된 방사패턴의 경우, 전체적으로 E면은 전방향성의 방사패턴을 갖고 있으면 H면은 다이폴 안테나의 전형적인 특성을 나타내고 있다

• 한국인터넷방송통신학회논문지
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• 제8권5호
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• pp.43-49
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• 2008

통방융합서비스가 가시화되면서 성능이 더욱 우수한 안테나 모델을 개발하기 위해 다양한 기술적 접근이 시도되고 있다. 본 논문은 핸드폰에 부착할 수 있고, 통방융합용에 적용할 수 있는 소형모바일 안테나를 제안한다. 모바일 핸드셑용 안테나 설계에서, 크기축소는 중요한 요소 중의 하나이며, 루프안테나의 소형화는 접어진 다이폴을 굽힘으로서 실현된다. 짧은 평면 다이폴은 더 큰 입력저항을 만들기 위해 두 배의 접어진 다이폴과 루프안테나로 변환된다. 그 안테나의 전류분포는 루프 안테나와 같고, 방사패턴은 전방향 특성을 갖는다. 또한 전기광학효과 맵핑 시스템을 이용하여 전류유기 근거리장 방사패턴에 의해 RFID안테나의 성능을 분석한다.

• 한국전자파학회논문지
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• 제16권1호
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• pp.84-91
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• 2005

본 논문에서는 PIFA(Planar Inverted F Antenna)의 방사부에 H형 슬릿을 부가하여 이중대 역 휴대이동전화기의 안테나 특성에 관하여 연구하였다. 안테나 방사부에 위치한 슬릿의 형태에 의하여 안테나의 임피던스의 리액턴스 성분에 영향과 공진 메카니즘을 변형함으로써 안테나의 공진특성에 영향을 준다. 그러므로 안테나는 이중대역(셀룰라 대역, 한국형 PCS 대역)에서 공진하며, 슬릿의 길이와 모양에 의해서 안테나의 대역폭, 입력 임피던스, 방사패턴 등에 영향을 미친다. 따라서 본 논문에서 제시한 이론의 타당성 및 객관성을 증명하기 위해서 H형의 슬릿을 이용하여 4종류의 안테나를 제작하여 실험한 결과 반사손실의 -5 dB 대역폭은 셀룰라 대역과 한국형 PCS 대역을 만족하였고, 안테나 이득은 약 -8$\~$-1 dB이며, x, y 편파에 대한 방사패턴은 대체적으로 전방향 방사패턴을 형성하였다. 따라서 본 논문의 결과를 이용함으로써 단말기용 내장용 안테나로 사용할 수 있음을 확인하였다.

• 전기전자학회논문지
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• 제3권1호
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• pp.1-10
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• 1999

In this paper, the design for the shaped offset cassegrain antenna system combined with corrugated feed horn is presented. First, spherical-mode wave theory is applied to the corrugated conical horn and its radiation patterns are investigated. Using the radiation patterns, design data of the corrugated conical horn are obtained by efficiency investigation of horn antenna. When the investigation is completed, the flare angle and length of the corrugated conical horn is determined. Next, the main and sub-reflector is designed using Snellis law and the conservation principle of energy. Then the uniform direction and energy density of the traveling wave at the aperture of the main-reflector is obtained. The maximum size of the main-reflector is determined by investigation of the illumination and spillover efficiency. Finally, the curvature of the main-reflector is modified to satisfy the condition of the uniform phase. From the calculated efficiencies, the designed site of the main-reflector and sub-reflector, system gain of the shaped offset cassegrain antenna has been obtained 40.5dB in Ka-band frequency. It has better characteristics than the result of SABOR with 39dB gain.

• Journal of information and communication convergence engineering
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• 제6권2호
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• pp.172-176
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• 2008

This paper presents a novel feeding structure of the triple-band internal antenna which covers CELLVLAR/DCS/US-PCS bands. The proposed antenna consists of a U-slot patch radiator with a shorting post connected with ground plane and symmetric feeding lines with respective a feeding and shorting posts on both faces of the fixed FR-4 substrate. Through the simulation and experimental results, the proposed antenna is confirmed to have the features of less interference with a human head/body, broad bandwidth, desirable radiation patterns and efficiency for triple-band applications.

• Journal of electromagnetic engineering and science
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• 제1권1호
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• pp.37-42
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• 2001

This paper presents the basic characteristics of a cutoff cavity-hacked slot antenna, for the application of spacetenna, with a feed post and a parasitic post inserted parallel to the slot. This type of antenna might effectively excite the slot and forcibly resonate the cavity by adding external reactance to the parasitic post. The Galerkin\`s method of moments is used to analyze integral equations for the unknown electric current on each post and electric field in the slot. The value of external reactance for forced resonance is discussed by deriving a determining equation, the current distribution on each post and the radiation patterns are considered. The analysis is in excellent agreement with the experiment for the radiation patterns.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제52권7호
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• pp.282-287
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• 2003

″H″ type resonator has the advantage for the miniaturization of high-T7 superconducting (HTS) microstrip antenna in comparison with the conventional microstrip antenna such as rectangular type or circular type. In this paper we designed miniaturized HTS antennas using this "H"-type resonator and reported the characteristics of our antennas including return loss, bandwidth, radiation patterns, efficiency and so on. To fabricate the "H" type antenna, HTS YBa$_2$Cu$_3$$O_{7-x}$ (YBCO) thin films were deposited on MgO substrates using rf-magnetron sputtering. For comparison between normal conducting antennas and superconducting antennas, the gold antennas with the same dimension were also fabricated. An aperture coupling was used for impedance matching between 50 $\Omega$ feed line and HTS radiating patch. The ″H" type superconducting antenna showed the performance of 1.38 in SWR, 26 % in efficiency, and 13.8 dB in the return loss superior to the normal conducting counterpart.

• Journal of electromagnetic engineering and science
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• 제5권2호
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• pp.97-103
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• 2005

This paper describes the measured results of sonobuoy transmitting antenna system for anti-submarine warfare (ASW). Since radiation pattern and power density depend on impedance matching between transmitting RF part and antenna with termination resistance, design of matching circuit is very important for sonobuoy system performance. Matching circuit is designed by Smith chart using control of L and C. In standing wave ratio(SWR) measurement using Network Analyzer, SWR of antenna with matching circuit observed 1.5 below at the assigned VHF band. It shows very excellent performance comparison with conversional product that is used for the same object. The measured vertical and horizontal radiation patterns are also shown the satisfaction of military specifications. A drop out of sonobuoy system on the sea is happened when angle of elevation direction is over 10 degrees, and it is conformed that it takes less than I second return to original signal level. The required electric power density is $83\;mW/m^2$ in the military specification, and measured electric power density is observed over average $110\;mW/m^2$ at all frequency bands.