• Title, Summary, Keyword: Antenna

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Design of Circularly Polarized Array Antenna for 5.8GHz Microwave Wireless Power Transmission (5.8GHz 마이크로파 무선전력전송을 위한 원형 편파 배열 안테나 설계)

  • Lee, Seong Hun;Son, Myung Sik
    • Journal of the Semiconductor & Display Technology
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    • v.17 no.2
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    • pp.20-25
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    • 2018
  • In this paper, we have designed circularly polarized array antenna for 5.8GHz microwave wireless power transmission. To obtain high antenna gain, we studied a single patch antenna, a $2{\times}1$ array antenna, a $2{\times}2$ array antenna, a $2{\times}4$ array antenna, and a $4{\times}4$ array antenna. Commonly, characteristics of each antenna have a frequency of 5.8 GHz and Right Hand Circular Polarization(RHCP) of circular polarization. Also, the results were obtained with the design to each antenna that the return loss was less than -10dB and the axial ratio was less than 3dB. The gain of the antennas was 6.08dBi for a single patch antenna, 9.69dBi for a $2{\times}1$ array antenna, 12.99dBi for a $2{\times}2$ array antenna, 15.72dBi for a $2{\times}4$ array antenna and 18.39dBi for a $4{\times}4$ array antenna. When the elements of the array antenna were increased, it was confirmed that it increased by about 3dBi.

A Superconducting $Y_1Ba_2Cu_3O_{7-\delta}$ Square Spiral Microstrip Antenna

  • Jung, Sung-H.;Song, Ki-Y.
    • Progress in Superconductivity
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    • v.2 no.1
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    • pp.51-55
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    • 2000
  • A $Y_1Ba_2Cu_3O_{7-\delta}$ square spiral microstrip antenna (YBCO antenna) was epitaxially grown on a $LaAlO_3$ substrate by laser ablation. Also fabricated was a gold square spiral microstrip antenna (gold antenna) having the same structure as that of the YBCO antenna in order to compare the properties of both antennas. Both the YBCO antenna and the gold antenna were operated in Ku (12-18 GHz) band, and their properties such as the return loss, SWR, power gain, and radiation patterns were investigated at 77 K. The return loss below -10 dB was obtained in two frequency ranges, i.e., 14.05-14.90 GHz, and 16-18 GHz for the YBCO antenna at 77 K (YBCO superconducting antenna), and in the frequency range of 15.05-17.60 GHz for the gold antenna at 77 K. The SWR bandwidths are 0.85 GHz and 2 GHz for the YBCO superconducting antenna, and 2.55 GHz for the gold antenna at 77 K. The gain improvement of the superconducting YBCO antenna over the gold antenna at 77 K was about 10 dB in the frequency range of 16 GHz to 18 GHz. The radiation patterns show the YBCO superconducting antenna has the omni-directional property of a spiral antenna.

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Design of the Pattern Adjustable Base Station Antenna for WCDMA Applications

  • Lee, Sang-Ho;Lee, Jung-Nam;Lee, Don-Shin;Park, Jong-Kweon;Kim, Hak-Sun
    • Journal of electromagnetic engineering and science
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    • v.8 no.2
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    • pp.64-69
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    • 2008
  • In this paper, we have proposed the pattern adjustable base station antenna for WCDMA applications. The proposed antenna consists of an omni-antenna(sleeve monopole) and two movable reflectors. The two reflectors can be controlled by mechanically and used to adjust the horizontal pattern of the base station antenna. The antenna was designed, fabricated, and measured. The antenna covers the entire WCDMA band for VSWR<1.4. The measured antenna gain is more than 15 dBi over the operating frequency range. By changing the angle (a) and the distance (d) of the antenna, the pattern adjustment of the proposed base station antenna is found to be possible.

Modeling and Design of Medium-wave DGPS Monopole Antenna (DGPS를 위한 중파대역 모노폴 안테나 모델링 및 설계)

  • Na, Sang-Geun;Lee, Su-Won;Kim, Young-Wan
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.18 no.4
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    • pp.797-804
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    • 2014
  • The experimental design method based-on the measured data in the several LF monopole antenna was used in MF monopole antenna design. The design technique is also utilized in MF DGPS antenna design. It is not possible to predict the antenna performance of the MF short-monopole antenna because of simple experimental antenna design. Furthermore, it is difficult to design and analyze the various wired short-monopole antenna. The antenna models for performance analysis of the DGPS antenna with the various wired short-monopole structure are proposed in this paper. Based on the proposed antenna models, also, the antenna performance and design data of the wired short-monopole antennas are presented. To evaluate the validity of the analyzed antenna models, the wired short-monopole antenna for 100 kHz are modeled and analyzed. The antenna performance of the wired short-monopole antenna are compared with those of the previously presented LF antenna performance. Based on the evaluation for proposed antenna analyzing models, the DGPS wired short-monopole antennas are modeled and analyzed.

Antenna factors of short dipole antennas with roberts balun (Roberts밸런을 갖는 단축 다이폴 안테나의 안테나 인자)

  • 김기채
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.22 no.3
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    • pp.532-538
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    • 1997
  • Exactly aclculated antenna factors are requeired for determining EMI levels in an actual radiated emission test. In this paper, the antenna factors of short dipole antennas above the ground plane are calculated theoretically for the antenna with Roberts balun specified ANSI C63.5 regulation. Also treated is a half-wavelength dipole antenna with Roberts balun to compare the antenna factors with those of resonant dipole antenna. In formulationof antenna factors the antenna is treated as the boundary value problem of Maxwells equations and is analyzed by the Galerkins method of moments. The balun is treated using circuit theory based on power transmission mismatch.

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Compact and Wideband Fylfot-Shaped Planar Monopole Antenna

  • Shim, Jae-Ruen
    • Journal of information and communication convergence engineering
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    • v.7 no.4
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    • pp.449-452
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    • 2009
  • In this paper, a novel compact and wideband fylfot-shaped planar monopole antenna is proposed. The fylfot-shaped is suggested to reduce the volume of a general crossed planar monopole antenna. The volume of the proposed antenna is about 1/4 of a general crossed planar monopole antenna under the conditions where the wideband characteristics are maintained. This technique is suitable for the design of wideband planar monopole antenna which needed a small volume.

Size Reduction of HF Whip Antenna (HF 휩 안테나의 소형화)

  • Lim, Ji-Hun;Lee, Young-Jin;Kim, Young-Jun;Choi, Sung-Jun;Jeon, Wo-Won;Park, Dong-Kook
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • pp.65-66
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    • 2012
  • For HF antenna, whip antenna with 6m length or more has been used generally. In this paper, we suggest a new HF antenna which is smaller than commercial HF whip antenna. The shape of the proposed antenna is "ㄷ" and the size of the antenna is $1m{\times}2m$. The feature of the antenna has been simulated by NECWin tools.

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Antenna Design with Combination of Electric-Magnetic Radiators for RFID System

  • Kim, Yong-Jin
    • Journal of electromagnetic engineering and science
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    • v.10 no.3
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    • pp.79-85
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    • 2010
  • In this paper, a directive antenna design with a combination of electric-magnetic radiators for an radio frequency identification(RFID) system is presented. To generate a directive antenna radiation pattern, a structure combining a dipole and loop antenna is presented. A reader antenna and tag antenna are proposed for the RFID system. For the reader antenna, the frequency bandwidth defined by $S_{11}$<-10 dB is approximately from 820~990 MHz. The forward and backward gain differences are 1.5~2 dBi. For the tag antenna, the frequency bandwidth is approximately from 860~920 MHz with a maximum gain of 3.58 dBi at 910 MHz. In both cases, directive radiation characteristics are observed.

Antenna Radiation Efficiency of the Korean NDGPS Based on Radiation Power Measurements

  • Kim, Young-Wan
    • Journal of information and communication convergence engineering
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    • v.10 no.2
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    • pp.97-102
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    • 2012
  • The differential global positioning system (DGPS) transmits a GPS enhancement signal using a top-loaded monopole antenna in the medium frequency range. The top-loaded antenna in the medium frequency band can attain a radiation efficiency on the order of 10%. The antenna ground plane characteristics affect the antenna radiation efficiency. To improve the radiation efficiency, it is necessary to install the antenna on a ground plane with large enough physical dimensions and good conductivity. The antenna radiation efficiency is a primary factor in determining the DGPS service area. The service area of the DGPS using a medium frequency band is dominantly affected by the antenna radiation efficiency. To determine antenna radiation efficiencies accurately, the antenna radiation efficiencies of DGPS are deduced from the propagation power in this paper. Based on the deduced antenna radiation efficiencies, the service area for the Korean nationwide-DGPS is analyzed and evaluated.