Browsing by Author "Hwang, R. -B."

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A Reconfigurable Antenna System Consisting of Post-wall E-plane Horns
(2010-01-01)
Hwang, R. -B.
;
Yen, H. -Y.
;
Yang, C. -S.
;
Chin, C. -Y.
;
Tsai, Y. -L.
In this article, we report a reconfigure antenna that is able to radiate different topologies of radiation pattern. Such an antenna system is composed of a four-way power divider made from a cavity-type structure fabricated using printed circuit technology. Due to the symmetric electric field distribution in the resonant cavity, the power divider maintains equal amplitude- and phase- distribution in the frequency range from 2.3 GHz to 2.5 GHz. Moreover, the high isolation among there ports was obtained. The output ports of the four-way power splitter respectively go through four radio frequency switches connected to four E-plane horn antennas. Notably, the four E-plane horns are integrated in a metallic parallel-plate structure equipped with four flared open ends. To enhance the isolation among the four E-plane horns, the metallic cylinders array is employed as a sidewall of the horn antenna. Moreover, prior to connecting to each horn antenna the signal is connected to a radio frequency switch to turn on (to the antenna) or off (to a terminator). Therefore, we can dynamically switch the beam among the four sectors. Specifically, the beam pattern covering several sectors can also be obtained. In addition to the numerical simulation of the overall antenna structure, we have fabricated this antenna and measured its radiation characteristics. The excellent agreement is obtained between the measured and simulated results.
SUBSTRATE INTEGRATED WAVEGUIDES WITH MOATS
(2009)
Hwang, R. -B.
;
Chin, C. Y.
;
電子工程學系及電子研究所
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Department of Electronics Engineering and Institute of Electronics
A substrate integrated waveguide (SIW) equipped with moats is investigated in this paper. Different from the commonly used SIW having dense via holes, this new SIW employed sparse via holes incorporating moats outside the via-hole arrays. Through numerous experimental studies, we found that it can maintain high transmission characteristics by introducing additional moats outside the via-hole arrays. Moreover, it is interesting to notice that such a new structure can lower its cutoff frequency and thus increase its operation bandwidth. Additionally, the calculation for the dispersion relation of such a new waveguide was carried out to understand its wave-guiding characteristics.