Ka Ming Mak

The University of Hong Kong, Hong Kong, Hong Kong

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Publications (6)5.13 Total impact

  • Kai Fong Lee, Kwai Man Luk, Ka Ming Mak
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    ABSTRACT: The technique of using U-slots to design dual/triple band patch antennas is applied to patch antennas fed by meandering (M) probes. It is found that the advantage of the M-probe, namely, low cross polarization, is preserved by the use of pairs of face-to-face U-slots. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 1498–1504, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25245
    Microwave and Optical Technology Letters 04/2010; 52(7):1498 - 1504. · 0.59 Impact Factor
  • Ka Ming Mak, Kwai Man Luk
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    ABSTRACT: A novel circularly polarized (CP) antenna with wide angular coverage is presented. The proposed antenna is formed by two bowtie patch antennas and two electric dipoles. It can achieve an impedance bandwidth (SWR < 1.6) of 41% and a 3-dB axial ratio bandwidth of 33%. For this design, very stable and symmetrical radiation patterns are obtained. In the axial ratio passband, the 3-dB beamwidth is 85<sup>deg</sup>plusmn2<sup>deg</sup> with a gain of 6.3 dBi plusmn0.3 dBi. The cross polarization is lower than -15 dB over a wide range of angles. For the entire half-power beamwidth, the axial ratio can be kept below 3 dB.
    IEEE Transactions on Antennas and Propagation 11/2009; · 2.33 Impact Factor
  • K.M. Mak, K.M. Luk
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    ABSTRACT: A novel circular-polarized antenna composed of bowtie patches, cross dipole and a power combiner is presented. Two air microstrip lines are utilized to feed the bowtie patches orthogonally. A 90-degree phase shift Wilkinson power divider is placed underneath the ground and connected to the feeds to generate circular polarization. The antenna attains an impedance bandwidth of 40.2% for return loss better than -15 dB and 3-dB axial ratio bandwidth of 29% (from 1.62 to 2.17 GHz). Very Stable and symmetric radiation patterns with low cross polarization level have been obtained over the operating frequency range. The 3-dB axial ratio beamwidth is about 90deg and the gain of the antenna is about 6.3 dBi with small variation.
    Antennas and Propagation Society International Symposium, 2007 IEEE; 07/2007
  • Hang Wong, Ka‐Ming Mak, Kwai‐Man Luk
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    ABSTRACT: A new wideband antenna employing a shorted bowtie patch for exciting a slot-type radiation is presented. Unlike a conventional directional slot antenna, which generally is placed 1/4-wavelength above a ground reflector, the height of the proposed antenna is 1/10-wavelength but a directional radiation can be achieved. The impedance bandwidth is 64% (SWR ≤ 2) from frequency of 2.07 to 4.02 GHz. The antenna does not only have a wideband feature but also has several attractive electrical characteristics such as symmetric radiation pattern, low cross polarization and stable pattern over the operating bandwidth. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 1670–1672, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21709
    Microwave and Optical Technology Letters 05/2006; 48(8):1670 - 1672. · 0.59 Impact Factor
  • Ka‐Ming Mak, Hang Wong, Kwai‐Man Luk
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    ABSTRACT: A high-gain wideband low-profile microstrip patch antenna array is designed and tested. A method for enhancing the impedance bandwidth through the combination of a driven rectangular patch with parasitic elements is proposed. The array, which has 16 elements in a 4 × 4 arrangement, is pasted on a 2-mm dielectric substrate. The impedance bandwidth and the gain of the array is 12% (for SWR ≤ 2) centered at 4.5 GHz and 20 dBi, respectively. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 729–730, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21458
    Microwave and Optical Technology Letters 02/2006; 48(4):729 - 730. · 0.59 Impact Factor
  • H. Wong, P.-Y. Lau, K.-M. Mak, K.-M. Luk
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    ABSTRACT: A small circularly polarised (CP) patch antenna with dual T-shaped probe feeds is presented. The patch is folded like a cap to generate a CP wave as well as to reduce the size of the antenna. The proposed antenna is operated at the centre frequency of 2.28 GHz with circular polarisation. The impedance bandwidth (SWR<2) is 21.8% from 2 to 2.49 GHz and the axial ratio bandwidth (AR<3 dB) is 3.5%. The measured gain is around 7.5 dBi. The antenna shows a good CP performance with a symmetric radiation pattern. The total area of reduction is 54% in comparison with the conventional half-wave patch antenna.
    Electronics Letters 01/2006; · 1.04 Impact Factor

Publication Stats

38 Citations
5.13 Total Impact Points

Institutions

  • 2007–2010
    • The University of Hong Kong
      • Department of Electrical and Electronic Engineering
      Hong Kong, Hong Kong
  • 2006
    • City University of Hong Kong
      • Department of Electronic Engineering
      Chiu-lung, Kowloon City, Hong Kong