The Experts below are selected from a list of 285 Experts worldwide ranked by ideXlab platform

Junji Yamauchi - One of the best experts on this subject based on the ideXlab platform.

  • a cavity backed Rectangular Aperture antenna with application to a tilted fan beam array antenna
    IEEE Transactions on Antennas and Propagation, 2003
    Co-Authors: Hisamatsu Nakano, M. Iwatsuki, M Sakurai, Junji Yamauchi
    Abstract:

    A Rectangular Aperture of A/sub x//spl times/A/sub y/, cut in the top conducting plate of a triplate transmission line and backed by a cavity, radiates a tilted beam off the direction normal to the Aperture. The mechanism of the radiation is explained using the Poynting vector distribution above the Aperture and the phase distribution of the electric field over the Aperture. The tilt angle is calculated as a function of side length A/sub x/ for a representative value of A/sub y/=18 mm=0.747/spl lambda//sub 12.45/, where /spl lambda//sub 12.45/ is the wavelength at a test frequency of 12.45 GHz. A tilted beam of approximately 27/spl deg/ is realized at A/sub x//A/sub y/=8/9 with a gain of approximately 8 dB. Using this value of A/sub x//A/sub y/, an array antenna composed of Rectangular cavity-backed Aperture elements is investigated. The array forms a tilted fan beam without phase shifters. The frequency responses of the gain and input impedance are discussed.

  • A Rectangular Aperture antenna with a tilted beam
    IEEE Antennas and Propagation Society International Symposium. Transmitting Waves of Progress to the Next Millennium. 2000 Digest. Held in conjunction, 1
    Co-Authors: Hisamatsu Nakano, M. Iwatsuki, Junji Yamauchi
    Abstract:

    For some antenna applications, for example, mobile communications, there is a requirement for the antenna to radiate a tilted beam. Previous investigation has shown that the beam tilt angle can be varied for a square Aperture antenna constructed using a triplate transmission line (TTL) by changing the side length of the square Aperture. However, an increased side length is undesirable when constructing an array antenna of square Apertures, because the increased side length makes the distance between the Aperture elements large and thus gives rise to undesired grating lobes. One way to avoid this drawback is to use a different Aperture shape. This paper presents a Rectangular Aperture antenna constructed using the TTL structure. The main purpose is to form a beam tilted from the direction normal to the antenna plane. The radiation characteristics of the Rectangular Aperture antenna are presented and discussed.

Kuanjung Hung - One of the best experts on this subject based on the ideXlab platform.

  • compact ultrawideband Rectangular Aperture antenna and band notched designs
    IEEE Transactions on Antennas and Propagation, 2006
    Co-Authors: Yicheng Lin, Kuanjung Hung
    Abstract:

    A simple and compact ultrawideband (UWB) Aperture antenna with extended band-notched designs is presented. The antenna consists of a Rectangular Aperture on a printed circuit board ground plane and a T-shaped exciting stub. The proposed planar coplanar waveguide fed antenna is easy to be integrated with radio-frequency/microwave circuitry for low manufacturing cost. The antenna is successfully designed, implemented, and measured. A compact Aperture area of 13 times23mm2 is obtained with promising performances, including broadband matched impedance, stable radiation patterns, and constant group delay. The correlation between the mode-based field distributions and radiation patterns is discussed. Extended from the proposed antenna, three advanced band-notched (5-6 GHz) designs are also presented as a desirable feature for UWB applications

Tarek Fortaki - One of the best experts on this subject based on the ideXlab platform.

  • effect of the thickness of high tc superconducting Rectangular microstrip patch over ground plane with Rectangular Aperture
    International Journal of Electrical and Computer Engineering, 2018
    Co-Authors: Nabil Boukhennoufa, Lotfi Djouane, Houcine Oudira, Mounir Amir, Tarek Fortaki
    Abstract:

    In recent years, a great interest has been observed in the development and use of new materials in microwave technology. Particularly, a special interest has been observed in the use of superconducting materials in microwave integrated circuits. This is due to their main characteristics. In this paper, the complex resonant frequency problem of a superconductor patch over Ground Plane with Rectangular Aperture is formulated in terms of an integral equation, the kernel of which is the dyadic Green’s function. Galerkin’s procedure is used in the resolution of the electric field integral equation. The surface impedance of the superconductor film is modeled using the two fluids model of Gorter and Casimir. Numerical results concerning the effect of the thickness of the superconductor patch on the characteristics of the antenna are presented.

  • Neurospectral modeling of Rectangular patch with Rectangular Aperture in the ground plane
    International Journal of Microwave and Wireless Technologies, 2014
    Co-Authors: Lotfi Djouane, Sami Bedra, Randa Bedra, Tarek Fortaki
    Abstract:

    In this study, we propose an artificial neural network in conjunction with spectral domain approach (SDA), for fast and accurate determination of the resonant frequency and half-power bandwidth of Rectangular patch over the ground plane with Rectangular Aperture. The performances evaluation of the neurospectral method reveals superiority over the conventional SDA model in terms of errors and time. The results obtained from the neurospectral method are in very good agreement with the experimental and theoretical results available in the literature. Finally, numerical results for the effect of Rectangular Aperture dimensions on the resonant characteristics of the Rectangular patch are also investigated.

  • Fourier Transform Domain Analysis of High T _ c Superconducting Rectangular Microstrip Patch over Ground Plane with Rectangular Aperture
    Journal of Infrared Millimeter and Terahertz Waves, 2010
    Co-Authors: Fouad Chebbara, Siham Benkouda, Tarek Fortaki
    Abstract:

    A rigorous full-wave analysis in the Fourier transform domain is carried out in order to obtain the resonant frequencies and half-power bandwidths of the high T _ c superconducting Rectangular microstrip patches over ground planes with Rectangular Apertures. To include the effect of the superconductivity of the microstrip patch in the full-wave analysis, a complex surface impedance is considered. This impedance is determined by using London’s equation and the two-fluid model of Gorter and Casimir. The validity of the solution is tested by comparison of the computed results with previously published data. Variations of the resonant frequency with the high T _ c superconducting film thickness are presented. Results showing the effect of the temperature on the resonant frequency and half-power bandwidth of the superconducting microstrip antenna with a Rectangular Aperture in the ground plane are also given. Finally, a comparison between the efficiency of two antennas is presented. For the first antenna, YBCO patch with YBCO ground plane are considered. For the second antenna, the patch and the ground plane are with copper.

Hisamatsu Nakano - One of the best experts on this subject based on the ideXlab platform.

  • a cavity backed Rectangular Aperture antenna with application to a tilted fan beam array antenna
    IEEE Transactions on Antennas and Propagation, 2003
    Co-Authors: Hisamatsu Nakano, M. Iwatsuki, M Sakurai, Junji Yamauchi
    Abstract:

    A Rectangular Aperture of A/sub x//spl times/A/sub y/, cut in the top conducting plate of a triplate transmission line and backed by a cavity, radiates a tilted beam off the direction normal to the Aperture. The mechanism of the radiation is explained using the Poynting vector distribution above the Aperture and the phase distribution of the electric field over the Aperture. The tilt angle is calculated as a function of side length A/sub x/ for a representative value of A/sub y/=18 mm=0.747/spl lambda//sub 12.45/, where /spl lambda//sub 12.45/ is the wavelength at a test frequency of 12.45 GHz. A tilted beam of approximately 27/spl deg/ is realized at A/sub x//A/sub y/=8/9 with a gain of approximately 8 dB. Using this value of A/sub x//A/sub y/, an array antenna composed of Rectangular cavity-backed Aperture elements is investigated. The array forms a tilted fan beam without phase shifters. The frequency responses of the gain and input impedance are discussed.

  • A Rectangular Aperture antenna with a tilted beam
    IEEE Antennas and Propagation Society International Symposium. Transmitting Waves of Progress to the Next Millennium. 2000 Digest. Held in conjunction, 1
    Co-Authors: Hisamatsu Nakano, M. Iwatsuki, Junji Yamauchi
    Abstract:

    For some antenna applications, for example, mobile communications, there is a requirement for the antenna to radiate a tilted beam. Previous investigation has shown that the beam tilt angle can be varied for a square Aperture antenna constructed using a triplate transmission line (TTL) by changing the side length of the square Aperture. However, an increased side length is undesirable when constructing an array antenna of square Apertures, because the increased side length makes the distance between the Aperture elements large and thus gives rise to undesired grating lobes. One way to avoid this drawback is to use a different Aperture shape. This paper presents a Rectangular Aperture antenna constructed using the TTL structure. The main purpose is to form a beam tilted from the direction normal to the antenna plane. The radiation characteristics of the Rectangular Aperture antenna are presented and discussed.

Yicheng Lin - One of the best experts on this subject based on the ideXlab platform.

  • compact ultrawideband Rectangular Aperture antenna and band notched designs
    IEEE Transactions on Antennas and Propagation, 2006
    Co-Authors: Yicheng Lin, Kuanjung Hung
    Abstract:

    A simple and compact ultrawideband (UWB) Aperture antenna with extended band-notched designs is presented. The antenna consists of a Rectangular Aperture on a printed circuit board ground plane and a T-shaped exciting stub. The proposed planar coplanar waveguide fed antenna is easy to be integrated with radio-frequency/microwave circuitry for low manufacturing cost. The antenna is successfully designed, implemented, and measured. A compact Aperture area of 13 times23mm2 is obtained with promising performances, including broadband matched impedance, stable radiation patterns, and constant group delay. The correlation between the mode-based field distributions and radiation patterns is discussed. Extended from the proposed antenna, three advanced band-notched (5-6 GHz) designs are also presented as a desirable feature for UWB applications