• Title/Summary/Keyword: Dipole Element

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Dualband Internal Antenna for GPS/PCS Handset (GPS/PCS 단말기용 듀얼밴드 내장형 안테나)

  • 정병운;이학용;이종철;김종헌;김남영;이병제;박면주
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.14 no.6
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    • pp.550-557
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    • 2003
  • In this paper, two dualband internal antennas for GPS/PCS handset are proposed. At first, the monopole antenna with parasitic dipole element is designed to print PCB of handset directly. At second, the antenna with bended loop structure is designed to bend to use internal space of handset maximumly. The proposed dualband internal antennas provide a 2:1 VSWR bandwidth of over 19.1 % which are possible to cover two bands at once. the antennas have a gain between -0.4 and 3.33 ㏈i at all bands and they have almost omni-directional patterns.

Design for the Circularly Polarized Microstrip Cross Dipole Array Antenna by Electromagnetic Coupled Technique (전자기 결합기법을 이용한 원편파 마이크로스트립 크로스 다이폴 어레이 안테나의 설계)

  • 민경식;임정남
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.12 no.1
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    • pp.50-57
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    • 2001
  • This paper describes a design for the circularly polarized microstrip EMC cross dipole array antenna with the wide bandwidth. To realize the characteristics of wide bandwidth and circular polarization, the electromagnetic-coupled cross dipole element is proposed. The optimum design parameters of a circularly polarized EMC cross dipole element are calculated by the FDTD and the Ensemble. To obtain the uniform aperture illumination of electric field in an array, offset technique that the cross dipole elements are alternatively arranged on center of the microstrip feed line is adopted. In 20-element array design, the calculated axial ratio and gain are about 0.1dB and 9.9 dBi at 12 GHz, respectively, The frequency characteristics of a fabricated 20-element array antenna are measured. The calculated results agree well with the measured ones.

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Design of V/UHF band Small Dipole Circular Array Active Antenna (V/UHF대역 소형다이폴 원형배열 능동안테나 설계)

  • Ko, Ji-Hwan;Lee, Cheol-Soo;Kim, Kang-Uk;Cho, Young-Ki
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.13 no.1
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    • pp.6-16
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    • 2009
  • For the application to the direction finding(DF) antenna for V/UHF bands, circular active array composed of 9 dipole element has been investigate. For miniaturization of the overall size array, the element has been chosen to be of the top-hat dipole type. For the broadband operation over 20-1300MHz, some number of pin diodes have been inserted in each arms of each dipole element. By employing this type of each element dipole, the effective dipole length can be increased or decreased according as the inserted pin diodes is on or off. The active array antenna has been design to be directly connected to the balanced push full amplifier such that the amplifier may play a role as a balloon and may improve the sensitivity as a receiver as well. The active array antenna has been designed and fabricated. Some experimental results have been presented in comparison with simulated results.

The radiation pattern calculation of the electromagnetically coupled microstrip dipole array antenna using the FDTD method (FDTD 방법을 이용한 전자기결합 마이크로스트립 다이폴 배열안테나의 복사패턴 계산)

  • 손영수;윤현보
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.22 no.7
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    • pp.1459-1467
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    • 1997
  • The current on the thin planar structure as an element of the transversely fed electromagnetically coupled(EMC) microstrip dipole array antenna is obtained by using the integral forms of the finite difference time domain(FDTD) method. This method was applied to calculating the optimum current distribution (Doplh-Tchebyscheff distribution) of each dipole element on the feed line as a function of their offset positions for the narrow main beam width and the side beam level below -20 dB. The current on each dipole substitutes for the electric and magnetic current densities on the virtual surface of the FDTD calculation to express the far field intensity, the calculation time and the computer memeory can be reduced to about 80% and 1.3 Mbyte, respectively. The calculated radiation patterns are compared to the measured values and these are in good agreement.

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Design of the Frequency Selective Surface with Transformation of Linear-to-circular Polarization (원편파 변환 주파수 선택 반사기 설계)

  • Ko, Ji-Whan;Cho, Young-Ki
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.38 no.1
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    • pp.34-42
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    • 2001
  • The new periodic array structure or frequency selective surface with polarizers characteristic is proposed. The present structure is constructed with two sheets or FSS material, spaced about one-eight wavelength apart, the dipole element orientations of the two sheets being almost perpendicular to each other. The methods of the spectral domain immittance and MoM are used to analyze electromagnetic scattering from this periodic array structure. To confirm the validity of the polrizer's functions or the new periodic array structure, frequency selective surfaces are fabricated, calculated values for the frequency response of the reflection and transmission loss are compared with measured values. Good correspondence has been observed between them. Good axial ratio has been also observed to be achieved in the proposed structure.

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Design of Super Wideband Dipole Antenna with 15:1 Impedance Bandwidth Ratio (15:1 임피던스 대역폭 비를 가지는 초광대역 다이폴 안테나 설계)

  • Yeo, Junho;Lee, Jong-Ig
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • pp.67-68
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    • 2013
  • In this paper, a super wideband printed dipole antenna operating in the band of 1-15 GHz is studied. A semi-circular-shaped dipole element is used to obtain a super wideband characteristic. Optimal design parameters are obtained by analyzing the effects of the gap between the two arms of the semi-circular-shaped dipole and the radius of the semi-circle on the input reflection coefficient and gain characteristics. The optimized printed semi-circular-shaped dipole antenna is fabricated on an FR4 substrate with a dimension of $100mm{\times}100mm$. Experimental results show that the antenna has a desired super wideband characteristic with a frequency band of 1-15 GHz (bandwidth ration 15:1, 175%) for a VSWR < 2.

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Applicator of Hyperthermia with Compact Dipole Antenna Array (소형화된 다이폴 안테나 배열 구조를 이용한 고온 온열 치료 전자기파 방사체)

  • Kim, Ki-Joon;Choi, Woo-Cheol;Choi, Jae-Hoon;Yoon, Young-Joong
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.23 no.2
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    • pp.244-250
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    • 2012
  • The compact dipole antenna elements and array structure is proposed. The array structure is designed for applicator in regional hyperthermia treatment to enhance the uniformity of the heat distribution which makes the treatment effective and prevents overheating. The compact dipole is designed with branched dipole and matching network to have small size and symmetric shape. The temperature simulation with specific absorption rate(SAR) and bio-heat equation is performed to have heat distribution. The applicator is designed, fabricated, and measured with multi-channel thermometer in 30 and 60 minutes. The simulation and measurement results showed agreement and the simulation in body circumstance has proper temperature result for hyperthermia therapy.

Miniaturized Design of Log-Periodic Dipole Array Antenna Using Half-Bowtie Dipole Elements (반-보우타이 모양 다이폴 소자를 이용한 대수-주기 다이폴 배열 안테나의 소형화 설계)

  • Yeo, Junho;Lee, Jong-Ig
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.20 no.6
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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.

Circular-Polarized Dipole Antenna with Reflector (반사판 부착 원편파 다이폴 안테나)

  • 한성민;이호선;우종명
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.11 no.7
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    • pp.1139-1146
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    • 2000
  • In this paper, circular-polarized dipole antenna with a novel structure is designed, simulated and fabricated for PCS or IMT-2000 base station at an arbitrary test frequency(1.575 GHz). Its radiation pattern is analyzed by means of physical optics(PO). The designed antenna is made up of a horizontal and a vertical dipole elements at a height of λ/4 above an reflector. One of λ/4 length vertical dipole element is located at a height of λ/8 above an reflector. In this case, circularly polarized radiation pattern is obtained by making impedance difference due to adjusting the length of each element. The characteristic of antenna measured from this study is that return loss is 18.4 dB, -10 dB bandwidth is 360 MHz(22.8%), 2 dB axial ratio bandwidth is 30 MHz, -3 dB beamwidth is 76$^{\circ}$, 2 dB axial ratio beamwidth is 58$^{\circ}$, axial ratio is 1.7 dB at 1.575 GHz. Radiation pattern is in well agreement with the result of PO.

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