Now showing 1 - 3 of 3
  • Publication
    ENG and NZRI Characteristics of Decagonal-Shaped Metamaterial for Wearable Applications
    ( 2020-08-01)
    Kabir Hossain
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    ;
    Soh Ping Jack
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    Fazilah, Ainur Fasihah Mohd
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    ;
    Raghava N.S.
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    Podilchak S.K.
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    Schreurs D.
    ;
    Abbasi Q.H.
    A decagonal-shaped split ring resonator metamaterial based on a wearable or textile-based material is presented in this work. Analysis and comparison of various structure sizes are compared considering a compact 6\times 6\ \mathrm{m}\mathrm{m}{2} metamaterial unit cell, in particular, where robust transmission-reflection (RTR) and Nicolson-Ross-Weir (NRW) methods have been performed to extract the effective metamaterial parameters. An investigation based on the RTR method indicated an average bandwidth of 1.39 GHz with a near-zero refractive index (NZRI) and a 2.35 GHz bandwidth when considering epsilon negative (ENG) characteristics. On the other hand, for the NRW method, approximately 0.95 GHz of NZRI bandwidth and 2.46 GHz of ENG bandwidth have been observed, respectively. These results are also within the ultra-wideband (UWB) frequency range, suggesting that the proposed unit cell structure is suitable for textile UWB antennas, biomedical sensors, related wearable systems, and other wireless body area network communication systems.
      3  55
  • Publication
    A Flexible and Compact Metamaterial UHF RID Tag for Remote Sensing in Human Health
    ( 2020-08-01)
    Ainur Fasihah Mohd Fazilah
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    ; ;
    Abbasi, Qammer Hussain
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    Kabir Hossain
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    ; ; ;
    Muhammad Ramlee Kamarudin
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    Majid, Huda Ahmad
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    Soh Ping Jack
    This paper presents a miniaturized UHF RFID tag antenna with increased gain using meander line techniques and metamaterial (MTM). The designed tag operates in the UHF RFID frequency band ranging from 860 to 960 MHz. It comprises of meandered lines with two hexagonal split ring resonators (H-SRRs) MTM cells. It is designed on a photo paper as its substrate which is 0.27 mm thick, with a dielectric constant of 3.2 and loss tangent of 0.05. Next, an RFID tag (NXP SL381213 UCODE G2iL chip) with an impedance of 23-j224 \Omega is integrated with the proposed antenna to assess its performance in terms of reflection coefficient, antenna gain and maximum reading range. The overall size of the tag is 92 mm x26 mm.
      3  25
  • Publication
    Green Nanocomposite-Based Metamaterial Electromagnetic Absorbers: Potential, Current Developments and Future Perspectives
    ( 2020-01-01)
    Yah N.F.N.
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    Soh Ping Jack
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    Abdulmalek M.
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    ; ;
    Seng, Lee Yeng
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    Jamaluddin M.H.
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    The use of the natural materials instead of conventional materials as electromagnetic absorbers promotes environmental sustainability, cost-effectiveness, and ease of accessibility. Furthermore, these materials may also be designed as absorbers and as reinforcements in building materials in a lightweight form. The absorbing ability of composite materials can be customized based on the chosen fillers. Specifically, magnetic and dielectric fillers can be incorporated to improve the absorption of a composite material compared to traditional materials. This work aims to review recent developments of electromagnetic absorbers enabled by nanocomposites, metamaterial and metasurface-based, as well as green composite alternatives. First, the background concepts of electromagnetic wave absorption and reflection will be presented, followed by the assessment techniques in determining electromagnetic properties of absorbing materials. Next, the state-of-the-art absorbers utilizing different materials will be presented and their performances are compared. This review concludes with a special focus on the future perspective of the potential of metamaterial based nanocellulose composites as ultrathin and broadband electromagnetic absorbers.
      40  2