Wee Fwen Hoon
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Preferred name
Wee Fwen Hoon
Official Name
Hoon, Wee Fwen
Alternative Name
Fwen Hoon, Wee
Wee, F. H
Hoon, Wee Fwen
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Scopus Author ID
57215069158
Researcher ID
CFL-8965-2022

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  • Publication
    Analysis of Dielectric Properties on Agricultural Waste for Microwave Communication Application
    ( 2017-12-11)
    Nurul Ain Zulkifli
    ;
    Wee Fwen Hoon
    ;
    Norfadila Mahrom
    ;
    Been Seok Yew
    ;
    Yeng Seng Lee
    ;
    Siti Zuraidah Ibrahim
    ;
    Anusha Leemsuthep Am Phan
    This paper presents the analysis of dielectric properties of agricultural waste for microwave communication application such as microwave absorber and antenna. The residues products - rice straw, rice husk, banana leaves and sugar cane bagasse were studied in the range between 1-20GHz. Firstly, the 2 types of resins namely Epoxy der 331 and Polyamine clear hardener were mixed with the agricultural waste materials to produce the small size of agricultural waste sample. Then, the sample were measured using PNA network analyzer. The permittivity and tangent loss of different agricultural waste samples have been measured using dielectric probe technique. Besides, other objectives of this paper is to replace the conventional printed circuit board (PCB) using FR4, Taconic, and Roger material with the agricultural waste material. Besides that, the different percentage of filer for each agricultural waste materials were also investigated to specify the best material to be used as the substrate board and as the resonant material. the result shows the average of dielectric constants and the average of the tangent loss of agricultural waste materials.
      3  24
  • Publication
    Side lobe suppression of Vivaldi antenna using shorting pin structure
    ( 2017-01-03)
    Wee Fwen Hoon
    ;
    Yew Been Seok
    ;
    Siti Julia Rosli
    ;
    Siti Nur Ainni Dzaaba
    ;
    Lee Yeng Seng
    This paper was executed in order to design side lobe suppression of Vivaldi antenna using shorting pin structure at S-band frequency. Nowadays, Vivaldi antenna has been used to satellite communications, remote sensing and radio telescope. There are a variety of designs such as tapered slot Vivaldi antenna, antipodal Vivaldi antenna and balanced antipodal Vivaldi antenna. Tapered slot Vivaldi antenna has been selected to design the project. The design of the antenna is start with patch antenna by using basis of transmission line model (TLM) formula to calculate the length and width of the patch. It is shaped into Vivaldi antenna. For the final design, the shorting pin structure will connect the patch on top side and the ground plane to absorb the unbalanced current. The shorting pin will reduce the side lobe. The antenna was simulated by using CST Microwave Studio. Based on the simulation results, the Vivaldi antenna shows a good performance as the return loss less than - 10 dB, voltage standing wave ratio, gain, directivity and radiation pattern was obtained the desired result as for a resonant frequency of 3 GHz. The radiation pattern of Vivaldi antenna with shorting pin structure reducing as compared with the design without shorting pin structure. The final antenna design shows that it has a few main lobe magnitudes where the antenna can focus and direct the energy for transmission or receiving of the energy signal.
      2  24
  • Publication
    Coconut shell, coconut shell activated carbon and beta-silicon carbide reinforced polymer composite: an alternative dielectric material for wireless communication application
    (Institute of Advanced Engineering and Science (IAES), 2020)
    Been Seok Yew
    ;
    Martini Muhamad
    ;
    Saiful Bahri Mohamed
    ;
    Wee Fwen Hoon
    The effect of coconut shell (CS), coconut shell activated carbon (CSAC) and beta-silicon carbide (β-SiC) in polymer composites was investigated. Elemental composition, surface morphologies and structural analyses of the fillers were performed using carbon, hydrogen, nitrogen and sulfur (CHNS) analyser, scanning electron microscope (SEM) and X-ray Diffractometer (XRD). The dielectric properties of the composites were measured using open-ended coaxial line method. CS and CSAC fillers had positive influence on the dielectric properties (ε’, ε” and σ) of the polymer composites, contributed by the orientation polarizations arises from polar nature of the amorphous CS and CSAC fillers. β-SiC filler had insignificant influence on the dielectric properties of the polymer composites due to its single polarization of the crystalline structure filler. This finding is in agreement with XRD patterns of CS and CSAC fillers that revealed the presence of amorphous structure with broad diffraction peaks that were detected at 2ϴ=22.236°, 34.8604° and 2ϴ=23.985° and 44.015°, respectively. The amorphization structure in the polymer composites allows the displacement and conduction currents that were induced from electric field to flow through the polymer composites when subjected to electromagnetic energy, thus increased the dielectric properties of the composites.
      8  1
  • Publication
    Dielectric properties measurement and pH analysis for drinking water
    (IOP Publishing Ltd., 2020)
    Wee Fwen Hoon
    ;
    Yew Been Seok
    ;
    Soh Ping Jack
    ;
    Lee Yeng Seng
    ;
    Lee Oon Keng
    Every material has its own dielectric properties and it is also the same for water. In this research, dielectric properties measurement on water will be done to examine the water quality of drinking water whether it is safe to drink or not. Water quality in Malaysia, as well as access to water in general, is a major problem. The primary pollutants present in the water are oils, rubbish, suspended solids, sewage and toxic substances. These are consequences of untreated or only partially treated sewage caused by human activities. Thus, water quality in Malaysia is currently of some concern. The normal drinking water pH range mentioned in World Health Organization (WHO) and National Drinking Water Quality Standards (NDWQS) guidelines is between 6.5 and 8.5. The water may contain some residue even though the pH is in the range of 6 to 7.5 so it does not prove that the water is safe enough for drinking purpose. Thereby, the analysis about the water quality using the specific measuring instruments need to carry out to prove that the water in neutral pH may not be safe to drink as the pH does not prove the content of the water as clearly as dielectric properties. High Temperature Coaxial Probe as the dielectric properties measurement sensor will be used to provide better information compare to pH. The measurement parameters that had been used to determine the water quality is the dielectric constant. The results obtained from both pH and dielectric properties measurement values are been analyzed and compared and it shows that pH value for clean and contaminated water is at almost similar values while dielectric properties results show different for both clean and contaminated water.
      21  1