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Subject: search.filters.subject.Circular ring

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    Design of circularly polarized unidirectional antenna using probe-excited circular ring antenna above the square reflector with inserted metallic slabs
    (2017-01-17)
    Phongcharoenpanich, Chuwong
    ;
    Lertsakwimarn, Kittima
    ;
    Sukkamat, Rungsinee
    ;
    Mhudtongon, Nattaset
    ;
    Kosulvit, Sompol
    This paper proposes a circularly polarized unidirectional antenna using a probe excited circular ring with inserted perpendicular slabs above the square reflector for UHF-RFID system. The measured S<inf>11</inf> ≤ -10 dB covers 884-1000 MHz or 12.31% bandwidth, and 3-dB AR bandwidth of 900-1000 MHz or 10.53% bandwidth. The maximum gain is 8.35 dBic. The half-power beamwidths in xz-and yz-planes are 66.3 and 66.7 degrees, respectively.
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    A bent probe excited circular ring antenna above cylindrical reflector radiating circular polarization
    (2007-12-01)
    Vongsack, Souphanna
    ;
    Phongcharoenpanich, Chuwong
    ;
    Kosulvit, Sompol
    ;
    Wakabayashi, Toshio
    This paper presents the characteristics of a bent probe excited circular ring antenna above cylindrical reflector radiating circular polarization for the point to point wireless Local Area Network communication system. The proposed antenna is operated at the center frequency of 2.45 GHz. The CST software based on FIT (Finite Integral Techniques) is used as the simulation tool for investigating the antenna characteristics. The probe was shielded by dielectric rod and it is bent to obtain good impedance matching and circular polarization. The simulated results of the return loss, radiation pattern, and axial ratio are presented. The antenna has an impedance bandwidth (2:1 VSWR) of 24.93% that cover the frequency range of 2.089 - 2.684 GHz. The antenna has a unidirectional pattern with maximum gain of 8.88 dBi. The average gain level is 8.18 dBi from simulation. The front-to-back ratio in both E-plane and H-plane is better than 20 dB.
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    A simple and cost-effective bidirectional antenna using a probe excited circular ring
    (2001-01-01)
    Kosulvit, Sompol
    ;
    Krairiksh, Monai
    ;
    Phongcharoenpanich, Chuwong
    ;
    Wakabayashi, Toshio
    This paper presents a simple and cost-effective bidirectional antenna using a probe excited circular ring. The structure of the antenna is simple i.e., a linear electric probe surrounded by the circular ring. The principle of the antenna design is easy and straightforward. A choice of the ring radius is first chosen to achieve the condition that only the dominant mode can be propagated. Furthermore, it is found that for a specific ring radius, the radiation patterns of the antenna are varied as the ring width. Then, the optimum ring width that provides the maximum directivity is determined. The criterion of the selection of the ring width for various ring radii is illustrated as the guidelines for the antenna design. The fabricated antennas at the operating frequency of 1.9065 GHz are measured and compared with the theoretical predictions. It is apparent that these results are in reasonable agreement. The bidirectional pattern with the gain of 5.4 dBi over the bandwidth of 17% is obtained. Moreover, the antenna can be easily fabricated with the low production cost. Therefore, this antenna is suitable for installing at the base station in the street cell.