• Journal of the Korea Institute of Information and Communication Engineering
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• 제20권6호
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• pp.1057-1062
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• 2016

In this paper, a design method for a compact log-perio dic half-bow-tie dipole array antenna for an operation in a UWB band(3.1-10.6 GHz) is studied. The proposed antenna is miniaturized by using half-bow-tie shaped dipole elements instead of strip-type dipole elements, which are commonly used in a general log-periodic dipole array(LPDA) antenna, and by reducing the element spacing. The effects of the flare angle of the half-bow-tie elements and the spacing factor on input reflection coefficient and realized gain characteristics of the proposed log-periodic antenna are analyzed. The optimized antenna is fabricated on an FR4 substrate, and the experiment results show that the antenna has a frequency band of 2.95-11.31 GHz for a VSWR < 2, which assures the operation in the UWB band. In addition, the length and width of the proposed antenna are reduced to 32.1 % and 18.3 %, respectively, compared to the LPDA antenna.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• 제14권11호
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• pp.1207-1215
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• 2003

In this paper Log-Periodic Bent Dipole Antenna(LPBDA), which is composed of bent dipole elements instead of dipole elements, is proposed to reduce the size of Log-Periodic Dipole Antenna(LPDA). LPBDA for the operating frequency band of 1 ㎓∼3 ㎓ is designed and its radiation characteristics are analyzed by the moment method, and compared with radiation characteristics of LPDA. It is shown that although LPBDA decreases in size by about 20 %, radiation characteristics of LPBDA are similar to radiation characteristics of LPDA. Calculated results show good agreement with measured results.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 한국정보통신학회 2018년도 추계학술대회
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• pp.526-528
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• 2018

This paper proposes a small, flexible dipole antenna for wireless power transmission of smart devices in a Wi-Fi environment. The proposed antenna is a mini-dipolar antenna structure with a split ring resonator in the center and is a small dipole antenna with a size of 32mm. The split ring resonator dipole antenna showed a reduction of about 20% compared to the same size of the dipole antenna.

• Proceedings of the KIPE Conference
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• 전력전자학회 2017년도 전력전자학술대회
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• pp.485-486
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• 2017

본 논문에서는 10m 반경의 공간에 위치한 웨어러블 기기를 충전하기 위한 무선 전력전송을 제안한다. 장거리 무선전력전송의 송신코일 양단의 높은 전압문제를 해결하기 위해 공진 커패시터를 분산하여 각 코일의 유기전압을 줄이는 분산권선형 다이폴 코일을 제안하였다. FEM 시뮬레이션 결과, 분산권선형 다이폴 코일이 형성한 자속밀도의 균일도는 최소 71%로 집중권선형 다이폴 코일의 최소 51%보다 높았다. 또한 거리별 최고 자속밀도는 분산권선형 다이폴 코일이 낮았지만 거리가 멀어질수록 차이는 줄어들어 5m 거리 이후에서의 차이는 30 % 이내임을 확인하였다. 시뮬레이션 설계를 바탕으로 분산권선형 다이폴 송신코일과 4가지의 다른 형태를 갖는 수신 코일을 제작하여 10m 거리 이내에서 10 mW 이상의 전력을 전송하였다.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• 제17권7호
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• pp.623-628
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• 2006

This paper presents the characteristics of an antenna factor of two kinds of EMI dipole antennas with a coaxial cable balun used in the frequency range between 30 and 1,000 MHz. The integral equation for unknown current distribution is solved by the Galerkin's method of moments with piecewise sinusoidal functions. An antenna factor for EMI dipole antennas with the coaxial cable balun is derived by using the power loss concepts. We can realize two kinds of EMI dipole antennas with appropriate antenna factors in the frequency range from 30 to 1,000 MHz: 150-cm dipole length($30{\sim}300 MHz$) and 30cm dipole length($300{\sim}1,000 MHz$). To check th ε validity of the theoretical analysis, the complex antenna factor was measured using by reference antenna methods. It is shown that the calculated complex antenna factor is good agreement with experimental results.

• The Journal of Korean Institute of Communications and Information Sciences
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• 제37C권12호
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• pp.1296-1302
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• 2012

In this research, optimization of a dual-band dipole array was performed using genetic algorithm. A non-uniform, aperture-shared linear array was configured with dipoles which resonate at 4 GHz and 9.5 GHz. The excited current distributions on dipoles were computed considering mutual coupling between dipole elements. The current distributions were also computed using method of moment (MoM). The optimization using genetic algorithm was performed to obtain the low sidelobe levels in two operating frequency band. The PSLs of the optimized array for 4 GHz and 9.5 GHz are -15.7 dB and -17 dB, respectively. Comparison between computed and simulated results are also discussed.

• Journal of Advanced Navigation Technology
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• 제26권1호
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• pp.29-34
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• 2022

In this paper, the design of a triple dipole quasi-yagi antenna operating in the 2.45 GHz and 5 GHz wireless LAN frequency bands and the 3.5 GHz WiMAX frequency band was studied. The proposed quasi-Yagi antenna consists of three dipoles connected in series with a V-shaped ground plane. The longest half-bow-tie-shaped dipole resonates in the 2.45 GHz band, whereas the medium-length dipole resonates at 3.5 GHz. The shortest dipole resonates in the 5 GHz band. By adjusting the length and width of the dipoles and the spacings between the dipoles, a triple-band directional antenna operating in the 2.45 GHz, 3.5 GHz, and 5 GHz bands are designed, and fabricated on an FR4 substrate with a size of 45 mm × 55 mm. It was confirmed that the fabricated antenna operates in the designed triple bands of 2.32-2.57 GHz, 3.26-3.69 GHz, and 4.50-6.56 GHz for a voltage standing wave ratio less than 2. Gain is maintained above 3 dBi in the three bands.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 한국해양정보통신학회 2004년도 춘계종합학술대회
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• pp.472-474
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• 2004

In this study, we investigated the characteristics of the input impedance and the gain of a ‘Folded dipole antenna with stub’ by the Method of Moments. The center frequency in this study is 200MHz, the radius of wire is 0.5nm, and the distance between two linear dipoles is 2cm. The inside variation of stub length within 18cm and the outside variation of stub length 4.5cm ive the value of SWR(Standing Wave Ratio) within 3. This means that the impedance matching between the ‘Folded dipole antenna with stub’ and receiver can easily be performed without a supplementary matching circuit.

• Journal of Korea Society of Industrial Information Systems
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• 제4권4호
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• pp.111-116
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• 1999

In this paper, the electromagnetically coupled microstrip dipole antenna by adapting one parasitic metal-strip(dipole) between the microstrip transmission line open end and the radiating microstrip dipole antenna is presented for the bandwidth improvement The microstrip dipole antenna is simulated using Ensemble 51 simulation package The effects of varying several physical parameters, such as the lengths of radiating dipole and parasitic dipole and the width of parasitic dipole are investigated The bandwidth behavior of the 3-layer optimum antenna is compared with that of 2-layer antenna without the parasitic dipole. Experimental result for the obtained broadband performance is presented and discussed.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• 제14권3호
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• pp.253-259
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• 2003

This paper presents the basic characteristics of a 5 element dipole array antenna which has a four parastic element and one driving element at the center of the circular array. The coupled integral equations for the unknown current distributions on dipole elements are derived and solved by applying Galerkin's method of moments. The numerical results show that the highest power gain of 7.8 dBi is obtained at radius of d = 0.3lλ when two short circuited parastic element neighbors. In order to verify the theoretical analysis, the radiation pattern is compared with Preston's results.