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Author: search.filters.author.Krairiksh, MonaiSubject: search.filters.subject.Bidirectional antenna

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    5.8 GHz notched UWB bidirectional elliptical ring antenna excited by circular monopole with curved slot
    (2007-12-01)
    Chawanonphithak, Krittaya
    ;
    Phongcharoenpanich, Chuwong
    ;
    Kosulvit, Sompol
    ;
    Krairiksh, Monai
    This paper presents a UWB bidirectional elliptical ring antenna excited by circular monopole with curved slot for 5.8 GHz band rejection. High Q operation of band notch is obtained in the simulation. The characteristics of the antenna have many attractive features in both technically and economically, such as bidirectional radiation pattern, wide impedance bandwidth, moderate gain, small size, low cost, and easy fabrication. The antenna is desired for application in conventional narrow and long path service area, where some frequency bands pre-occupied by the WLAN standard IEEE 802.11a.
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    An ultra-wideband bidirectional antenna with modified circular disc monopole excited elliptical ring
    (2007-08-28)
    Chawanonphithak, Krittaya
    ;
    Phongcharoenpanich, Chuwong
    ;
    Kosulvit, Sompol
    ;
    Krairiksh, Monai
    The antenna design for ultra-wideband (UWB) signal radiation is one of the main challenges of the UWB system, especially when the antenna can satisfy the requirement of low-cost, compactness, linear polarization and bidirectional pattern. This paper proposes a UWB bidirectional antenna with introducing the ψ shape feeder to circular disc monopole (CDM) excited elliptical ring for modern base station in UWB system. The simulation results are presented UWB performance of this antenna by using Computer Simulation Technology (CST®). The return loss of better than 10 dB covers the frequency range from 3 to 25 GHz, directivity at the direction toward θ=0° and 180° from 2.8 dBi at 3 GHz to 4.6 dBi at 11 GHz. The proposed antenna can achieve bidirectional pattern over the bandwidth of 7.5 GHz. The bidirectional radiation pattern is desirable for many applications in long and narrow path service cell. ©2007 IEEE.
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    NEC simulation of a bidirectional antenna using a probe excited elliptical ring
    (2005-12-01)
    Chawanonphithak, Krittaya
    ;
    Phongcharoenpanich, Chuwong
    ;
    Krairiksh, Monai
    This paper describes the characteristics of a bidirectional antenna using a probe excited elliptical ring. Based on the waveguide principle, a design of elliptical ring cross section that yields the propagation in dominant mode can be chosen and clarified by Numerical Electromagnetic Code (NEC). The quarter wavelength probe can accomplish matching condition. Subsequently, a decision of the ring length that obtains the desired directivity as well as the efficient radiation pattern, standing wave ratio (SWR), polarization, and bandwidth can be found by simulation. To investigate the characteristics of the proposed antenna for applying at the base stations, the wired grid model must be constructed. Using NEC simulation, the antenna characteristics can be carried out. The antenna prototype is fabricated and tested to verify the validity of our design method and the usefulness in Thai Mobile system operated at the center frequency of 1.92 GHz, The proposed antenna radiating bidirectional beam is suitable for narrow and long path service area with simple configuration and cost effective. © 2005 IEEE.
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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.