• Title/Summary/Keyword: antenna gain

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Design of a Wideband Antipodal Vivaldi Antenna with an Asymmetric Parasitic Patch

  • Bang, Jihoon;Lee, Juneseok;Choi, Jaehoon
    • Journal of electromagnetic engineering and science
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    • v.18 no.1
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    • pp.29-34
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    • 2018
  • An antipodal Vivaldi antenna with a compact parasitic patch to overcome radiation performance degradations in the high-frequency band is proposed. For this purpose, a double asymmetric trapezoidal parasitic patch is designed and added to the aperture of an antipodal Vivaldi antenna. The patch is designed to efficiently focus the beam toward the end-fire direction at high frequencies by utilizing field coupling between the main radiating patch and the inserted parasitic patch. As a result, this technique considerably improves the gain and stability of radiation patterns at high frequencies. The proposed antenna has a peak gain greater than 9 dBi over the frequency range of 6-26.5 GHz.

A Small Microstrip Patch Antenna (소형 마이크로 스트립 패치안테나)

  • 장순범;박동국
    • Proceedings of the Korea Electromagnetic Engineering Society Conference
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    • 2002.11a
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    • pp.246-249
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    • 2002
  • In this paper, a rectangular patch antenna is miniaturized by changing tile middle of patch into narrow microstrip line except the edges of the patch where the fringing field occurs. Miniaturizing rate, gain, radiation patterns of suggested antennas were compared with general square microstrip antenna by using simulator Ensemble. As a result, it reduces the size of antenna by 30% and improves the characteristic of X pol as a advantage while it reduces gain and bandwidth.

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Dual Band Antenna of 433 MHz and 920 MHz for Marine Buoy (해양 부이용 433 MHz와 920 MHz 이중 대역 안테나)

  • Seong-Real Lee
    • Journal of Advanced Navigation Technology
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    • v.25 no.6
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    • pp.523-529
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    • 2021
  • This paper shows the design and fabrication of antenna embedded in marine buoy for marine IoT service, especially automatic identification system of fishing gears. Frequency band of proposed antenna has dual band of 433 MHz and 920 MHz considering marine IoT extension. Dual pattern monopole type for 920 MHz and meander type for 433 MHz are adopted in the proposed antenna. Voltage standing wave ratio is obtained 1.548 at 433 MHz and obtained 1.5 of mean value at 920 MHz band by measuring the fabricated antenna. The maximum antenna gain of 3.83 dBi is measured at 902 MHz among 920 MHz band, while antenna gain of 433 MHz is obtained 1.18 dBi. Although antenna gain of 433 MHz is low than 920 MHz band, this gain is larger than desired value of -5 dBi. And, it is confirmed that other measured values meet the performance criteria for archiving communication distance of 10 km between marine buoy and fishing ship in automatic identification system of fishing gears.

Gain Enhancement of a Circularly-Polarized Patch Antenna with a Double-Layered Superstrate for Wireless LAN (무선 LAN용 원형편파 패치안테나에 이중 적층 상부덮개를 적용한 이득 향상)

  • Lee, Sangrok
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.40 no.12
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    • pp.2427-2433
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    • 2015
  • A high-gain circularly-polarized patch antenna with a double-layered superstrate is proposed operating at a wireless LAN frequency. A superstrate has an array of metallic periodic unit cells and is located above the patch antenna with an air-gap. The designed antenna has a high gain of over 9.59dBi, which is the gain enhancement of 6.48dB compared to the patch antenna without superstrate. And it has a low axial ratio of under 3dB, so that it maintains the circular polarization of the patch antenna. The optimum air-gap height at the superstrate of $4{\times}4$ arrays is 25mm, which is equivalent to about $0.2{\lambda}$ at the frequency of 2.45GHz. We confirmed that the double-layered stacking of a superstrate increases the effective aperture size and hence it leads to enhance a gain of the patch antenna.

High-Efficiency, High-Gain, Broadband Quasi-Yagi Antenna and Its Array for 60-GHz Wireless Communications

  • Ta, Son Xuat;Kang, Sang-Gu;Han, Jea Jin;Park, Ikmo
    • Journal of electromagnetic engineering and science
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    • v.13 no.3
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    • pp.178-185
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    • 2013
  • This paper introduces a high-efficiency, high-gain, broadband quasi-Yagi antenna, and its four-element array for use in 60-GHz wireless communications. The antenna was fed by a microstrip-to-slotline transition consisting of a curved microstripline and a circular slot to allow broadband characteristics. A corrugated ground plane was employed as a reflector to improve the gains in the low-frequency region of the operation bandwidth, and consequently, to reduce variation. The single antenna yielded an impedance bandwidth of 49 to 69 GHz for $|S_{11}|$ <-10dB and a gain of >12.0 dBi while the array exhibited a bandwidth of 52 to 68 GHz and a gain greater than 15.0 dBi. Both proposed designs had small gain variations (${\pm}0.5$ dBi) and high radiation efficiency (>95%) in the 60-GHz bands. The features of the proposed antenna were validated by designing, fabricating, and testing a scaled-up configuration of the single antenna at the 15-GHz band. The measurements resulted in an impedance bandwidth of 13.0 to 17.5 GHz for $|S_{11}|$ <-10dB, a gain of 10.1 to 13.2 dBi, and radiation efficiency in excess of 88% within this bandwidth. Additionally, the 15-GHz antenna yielded quite symmetric radiation profiles in both E- and H-planes, with a high front-to-back ratio.

A Study on a Gain-Enhanced Antenna for Energy Harvesting using Adaptive Particle Swarm Optimization

  • Kang, Seong-In;Kim, Koon-Tae;Lee, Seung-Jae;Kim, Jeong-Phill;Choi, Kyung;Kim, Hyeong-Seok
    • Journal of Electrical Engineering and Technology
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    • v.10 no.4
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    • pp.1780-1785
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    • 2015
  • In this paper, the adaptive particle swarm optimization (APSO) algorithm is employed to design a gain-enhanced antenna with a reflector for energy harvesting. We placed the reflector below the main radiating element. Its back-radiated field is reflected and added to the forward radiated field, which could increase the antenna gain. We adopt the adaptive particle swarm optimization (APSO) algorithm, which improves the speed of convergence with a high frequency solver. The result shows that performance of the optimized design successfully satisfied the design goal of the frequency band, gain and axial ratio.

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.

High-Gain and Wideband Microstrip Antenna Using Glass/Epoxy Composite and Nomex Honeycomb (유리섬유/에폭시 복합재료와 허니컴을 이용한 고성능의 마이크로스트립 안테나 설계)

  • You C.S.;Hwang W.
    • Proceedings of the Korean Society For Composite Materials Conference
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    • 2004.04a
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    • pp.1-4
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    • 2004
  • In this paper we developed Composite-Smart-Structures(CSS) using sandwich structure composed of Glass/Epoxy laminates and Nomex honeycomb and microstrip antenna. Transmission/reflection theory shows that antenna performances can be improved due to multiple reflection by Glass/Epoxy facesheet, and honeycomb is used for air gap between antenna and facesheet. Stacked radiating patches are used for the wideband. Facesheet and honeycomb thicknesses are selected considering both wideband and high gain. Measured electrical performances show that CSS has wide bandwidth over $10\%$ and higher gain by 3.5dBi than initially designed antenna, and no doubt it has excellent mechanical performances by sandwich effect given by composite laminates and honeycomb core. The CSS concept can be extended to give a useful guide for manufacturers of structural body panels as well as antenna designers, promising innovative future communication technology.

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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.

Design and Implementation of Koch curve Microstrip Patch Antenna for Antenna Miniaturization (안테나 소형화를 위한 koch curve 마이크로스트립 패치 안테나 설계 및 구현)

  • Kim, Sun-Woong;Lim, Dong-Seob;Kim, Young-Gon;Choi, Dong-You
    • Journal of Information Technology Services
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    • v.12 no.3
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    • pp.323-330
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    • 2013
  • In this paper, miniaturized patch antenna operating at ISM band has been designed by applying the fractal technique. Various type of antenna structure, microstrip patch antenna and koch curve microstrip patch antenna has been proposed and simulated using Ansoft HFSS (High Frequency Structure Simulator). The area of microstrip patch antenna and koch microstrip patch antenna is 1,058 $mm^2$, and 891 $mm^2$ respectively, showing the size reduction ratio of 16%. The finally made koch curve microstrip patch antenna resonates at 2.45GHz with return loss of 22.69dB, VSWR of 1.2142, and antenna radiation gain of 3.26dBi.