Browsing by Author "Hwang, Ruey Bing"

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A band-pass filter using via-hole-wall cavity
(2007-06-01)
Hwang, Ruey Bing
;
Pan, Jun Liang
;
電信工程研究所
;
Institute of Communications Engineering
In this paper, we presented a band-pass filter-consisting of a post-wall cavity, resonator. This band-pass filter was fabricated in a two-layered printed circuit board, which includes an input and an output substrate integrated waveguides as the feeding structures in the top layer and a cavity in the bottom layer. The interconnection of the signal between different layers is achieved via the apertures etched on the input and output waveguides and cavity. We found the bandwidth of such a class of band-pass filter could be altered by tuning the length of the coupling apertures. Besides, the pass-band frequency can be estimated by the resonant frequencies of the cavity. We have fabricated the bandpass filter on a low-loss dielectric substrate and measured its S-parameters, including the return- and insertion-loss. In addition, the numerical simulation by the CST microwave studio, a full-wave time-domain numerical method, was also carried out. A good agreement between the measured and simulation results was obtained. (c) 2007 Wiley Periodicals, Inc.
A planar shaped-beam antenna for indoor wireless LAN access points
(2007-06-01)
Hwang, Ruey Bing
;
Pu, Ta Chun
;
電信工程研究所
;
Institute of Communications Engineering
A planar antenna is described that is made up of a;ne source embedded in a structure containing a metal reflector and a dielectric layer coated with metal strips. We have fabricated and measured the radiation characteristics, including the return loss and radiation pattern. In addition to the experimental studies, the rigorous mode-matching method incorporating the equivalent principle was employed to calculate the electromagnetic fields in the structure and the far-field radiation pattern, as well. Besides, the sensitivity analyses for the radiation pattern against the variations on the structure parameters and relative dielectric constant,,ere carefully carried out. The good agreement between the measured and calculated results was found. Combining the leak-waves and space-wave radiating from this structure, such a linearly polarized antenna can radiate a rectangular footprint of uniform electric-field strength, with 9% bandwidth around 11.4 GHz.
Characterization and design of cylindrical microstrip leaky-wave antennas
(2008-07-01)
Lin, Lieh-Chuan
;
Miyagawa, Hayato
;
Kitazawa, Toshihide
;
Hwang, Ruey Bing
;
Lin, Yu-De
The spectral-domain approach is applied for the analysis and the design of the cylindrical microstrip leaky-wave antenna. The first higher-order leaky-mode is thoroughly investigated. We perform the well-known spectral-domain approach and Galerkin's method to acquire the complex propagation constants of leaky modes, which are verified with results obtained by the scattering-parameter extraction technique. Two practical antennas are designed and implemented. Measured return loss and radiation patterns show a good performance of these cylindrical antennas, compared to that of the planar ones.
Omnidirectional stop band by using composite two dimensionally artificial crystal
(2007-08-01)
Hwang, Ruey Bing
;
Pu, Ta Chun
;
電信工程研究所
;
Institute of Communications Engineering
We present here a study of the wave propagation in a two-dimensionally (2D) periodic structure. The scattering of a plane wave by a 2D periodic structure is analyzed as a multilayer boundaryvalue problem. Specific examples are given to show quantitatively the stopband behaviors; in particular, a composite structure with different lattice patterns in cascade is shown to achieve the broad and omnidirection behavior of stop band. (c) 2007 Wiley Periodicals, Inc.
RESONANCE TRANSMISSION THROUGH ELECTROMAGNETIC CRYSTALS CONSISTING OF METAL STRIPS
(2009-05-01)
Hwang, Ruey Bing
;
電信工程研究所
;
Institute of Communications Engineering
In this letter, we present frequency-selective transmission of a 2D (two-dimensionally) electromagnetic (EM) crystal. Such a 2D EM crystal consists of a finite stack of one-dimensionally metal-strip gratings. The rigorous mathematical formulation using the mode-matching method incorporating the Floquet solution was employed to calculate the scattering and guiding characteristics of the structure under consideration. Additionally, the experimental studies were also carried out to verify the numerical results. Significantly, the correlation between frequency-selective transmission and the Fabry-Perot resonance was clarified. (C) 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 1209-1212, 2009; published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24280