C.Y. Chiu

The University of Hong Kong, Hong Kong, Hong Kong

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Publications (3)3.66 Total impact

  • C.Y. Chiu, H. Wong, C.H. Chan
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    ABSTRACT: A small wideband patch antenna which exhibits an impedance bandwidth (Voltage Standing Wave Ratio (VSWR) les 2) of more than 70% with an antenna size of 0.314lambda<sub>o</sub>times0.314lambda <sub>o</sub>times0.146lambda<sub>o</sub> (where lambda<sub>o</sub> is the guided wavelength of the centre operating frequency) is presented. Bandwidth broadening is achieved by an E-shaped patch fed by a folded-patch feed, whereas the size reduction is realised through the use of a shorting wall. As the antenna can be made from a single piece of copper plate, it is easier to fabricate than the wideband U-shaped-slot and L-shaped-slit folded-patch-feed antennas previously reported. Parametric studies of the proposed antenna are performed numerically to review its radiation mechanism. These include the purposes of having a shorting wall and two arms attaching on the upper patch forming the E-shaped pattern and the analysis of the input impedance of the antenna. Approximate equations for designing the proposed antenna are also presented. To verify the working principle, the proposed antennas are fabricated and tested for three different frequency bands. Stable radiation patterns are obtained across the band
    IET Microwaves Antennas & Propagation 05/2007; · 0.84 Impact Factor
  • Chi Yuk Chiu, Kam Man Shum, Chi Hou Chan
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    ABSTRACT: A novel tunable planar inverted-F antenna (PIFA) is described. A via-patch is introduced under the main radiating element to create a capacitive coupling effect and lower the operating frequency. The antenna size is reduced by half when compared to the conventional PIFA. Incorporating with an L-shaped opening on the ground plane, the proposed via-patch loaded PIFA exhibits a 10-dB return-loss bandwidth of 8.91% for 2.4 GHz ISM band applications. In the proposed approach, the capacitive patch is connected to the ground through a via while a coaxial feed is directly connected to the radiating element. This is different from other capacitive-loading, size-reduction schemes in which the capacitive patch is connected to the coaxial feed, thus not able to provide frequency tuning. By simply replacing the via in our antenna with a screw and adjusting the height of the via-patch by turning the screw, a tuning range of 0.8 GHz from 2.5-3.3 GHz can be achieved. This makes the proposed PIFA a convenient tunable small antenna. Both simulation and measurement results are presented together with parametric studies on the via-patch and L-shaped opening ground plane
    IEEE Transactions on Antennas and Propagation 02/2007; · 2.33 Impact Factor
  • C.Y. Chiu, C.H. Chan, K.M. Luk
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    ABSTRACT: A series of simulations and experimental investigations, of slotted microstrip patch antennas with a folded patch feed, are presented. The analysis includes the effects of varying the location of the feed and the shape of slot. All the investigated antennas are fed by a bandwidth-enhanced feeding method: folded patch feed. The folded patch feed is an attractive tailor-made feeding method for microstrip patch antennas, resulting in an impedance bandwidth (VSWR≤2) of more than 50%. In the study, the folded patch feed has been applied to different shapes of slots, and some of them profit with a wider impedance bandwidth over a rectangular U-slot shape. Among all the examined antennas, a trapezoidal slot microstrip patch antenna with an additional aperture and a shorting wall has an impedance bandwidth of 76.37%.
    IEE Proceedings - Microwaves Antennas and Propagation 11/2005; · 0.49 Impact Factor