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
Main Affiliation
Scopus Author ID
57215069158
Researcher ID
CFL-8965-2022

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  • Publication
    Parametric studies on effects of defected ground structure (DGS) for dual band bandstop microstrip filter
    ( 2017-11-22)
    Farah Shazuani Mahmud
    ;
    Mohammad Shahrazel Razalli
    ;
    Hasliza A Rahim @ Samsuddin
    ;
    Wee Fwen Hoon
    ;
    Mohd Zaizu Ilyas
    A dual-band bandstop microstrip filter is proposed and designed by using microstrip resonator with Defected Ground Structure (DGS). The DGS are placed in the ground plane to obtain high attenuation of the bandstop filter response. The proposed is designed by using R04003C printed circuit board with dimension of 38 mm x 20 mm. Simulated result shows an insertion loss of -12.31 dB, a return loss at -1.75 dB for center frequency at 2.4 GHz and insertion loss of -22.93 dB, a return loss of -0.78 dB for center frequency at 5.8 GHz The results of simulated in different parameters of DGS is analysed and discussed.
  • Publication
    Design of Ultra-Wideband Monopole Antenna for EMC Application
    ( 2023-10-06)
    Wee Fwen Hoon
    ;
    Yew B.S.
    ;
    Siti Zuraidah Ibrahim
    ;
    Lee Y.S.
    In this era of technology, EMC application have become more important because the increase of electronic devices due to the demand from users. Every electronic appliance is a source of radiated electromagnetic fields called radiated emission. Hence, it is important to make sure the radiation is in a safe level where an antenna will be used to detect the radiated electromagnetic fields. The existing antenna used for EMC testing such as log-periodic antenna, fractal antenna and biconical antenna have a large dimension that make it hard to set up for the testing and majority can only operate starting from 3 GHz and above. In order to overcome that problem, an ultra-wideband monopole patch antenna is proposed which aimed to be operated from 0.7 to 6.8 GHz for EMC testing. The UWB antenna can be achieved by having a truncated ground plane and notches at the ground structure. The edges of the rectangular patch antenna have been cut to improve the return loss and a tapered feed is implemented to increase the gain. To design and simulate the proposed antenna, CST Microwave Studio software has been used in this project to get the desired result which is the return loss and gain. The design for this antenna is very simple to ease the fabrication process. Overall, the structure consists of an antenna patch with a rounded rectangular shape, tapered feed line, and a truncated ground plane with notches at both corners. The simulation result of reflection coefficient of the antenna is at 0.7 GHz up to 6.8 GHz which has a high bandwidth efficiency at 162%, and have a good gain which is in around 2 to 5.6 dB if compared to the previous study by [1], as the bandwidth efficiency was 109% and gain values varies between 1 to 3.83 dB only.
  • Publication
    Flexible Co-Planar Waveguide (CPW)-Fed Y-Shaped Patch UWB Antenna for Off-Body Communication
    ( 2020-03-18)
    Kassim S.
    ;
    Hasliza A Rahim @ Samsuddin
    ;
    Soh Ping Jack
    ;
    Abdulmalek M.
    ;
    Muzammil Jusoh
    ;
    Jamaluddin M.H.
    ;
    Sabli N.S.
    ;
    Yassin M.N.
    ;
    Thennarasan Sabapathy
    ;
    Wee Fwen Hoon
    ;
    Mohamed Nasrun Osman
    ;
    Ismail N.
    This paper intends to design an Ultra-Wideband (UWB) antenna for future Internet of Things (IoT) applications for off-body Wireless Body Area Networks (WBAN) communication. An antenna based on the Y-shaped patch fed using co-planar waveguide (CPW) line, with a full ground plane is designed. It is implemented on two different substrates, namely a 5mm thick Rogers RO4350B and a 5-mm-thick felt textile. Parametric analysis of antenna is performed by changing its critical dimensions and monitoring parameters such as gain, bandwidth, efficiency, radiation pattern when using both substrates. Besides that, the bending effects towards reflection coefficient and radiation patterns are also studied. The final patch size with the Y-shaped slot is 36 × 40 mm2 for both substrates. The antenna is capable of providing coverage for the bands from 8 to 10 GHz. Finally, the antenna designed on RO4350B substrate outperforms the antenna designed on felt by about four times in terms of bandwidth, with 3.3 GHz (7.7-11 GHz).
  • Publication
    Beam controller antenna for WiMAX application
    ( 2017-01-01)
    Leong Lim Wai
    ;
    Wee Fwen Hoon
    ;
    Yeow You Kok
    ;
    Mohd Fareq Abdul Malek
    ;
    Yew Lee Chia
    ;
    Seng Lee Yeng
    ;
    Siti Julia Rosli
    Introduce a practical design of an antenna that able to control the radiation beam pattern by using PIN diode and capacitor. The operation of the antenna is an on/off switch that controlled by PIN diode and Direct Current (DC) that supply from an an external source. The proposed antenna was verified to be able to cover the direction of 90 degreess when the DC is turn on. The DC pass through the PIN diode and activate the diode to be functioned as a switch. This proposed antenna is operated at a frequency of 2.3 GHz which is for Worldwide Interoperability for Microwave Access (WiMAX) application that symbolizes in the IEEE 802.16 family. This antenna is designed using a FR-4 substrate material with the dimension is 200 mm×200 mm using Computer Simulation Technology Microwave Studio (CST MWS) simulator software.
  • Publication
    Flexible RFID Tag Antenna Design
    ( 2020-01-01)
    Wee Fwen Hoon
    ;
    Abdul Malek M.F.
    ;
    Yew B.S.
    ;
    Lee Y.S.
    ;
    Ibrahim S.Z.
    ;
    Hasliza A Rahim @ Samsuddin
    This research is to design a radio frequency identification (RFID) high sensitivity tag antenna which operates at UHF frequency band (919–923 MHz). The major problem in designing the tag antenna is that it needs to be designed for long-range transmission with a miniaturized size. However, reducing the size of the tag antenna can cause the gain to be decreased. Another challenge in designing RFID passive tag is to ensure no huge change occurs on the resonant frequency when the tag antenna is being bent. This research had provided two methods in overcoming those problems that include the construction of a meander line structure to reduce the antenna size that can be applied to a small device. In addition, flexible substrate, polyethylene terephthalate (PET) had been chosen for tag antenna. Thus, the expected result shows high gain (1.55 dB) with a small size of flexible tag antenna.
  • 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.
  • Publication
    A review of oil palm fruit ripeness monitoring using microwave techniques in Malaysia
    (IOP Publishing, 2020)
    K Y You
    ;
    Wee Fwen Hoon
    ;
    Y S Lee
    ;
    Z Abbas
    ;
    K Y Lee
    ;
    Cheng Ee Meng
    ;
    C S Khe
    ;
    Mohd Faizal Jamlos
    Palm oil products are one of the most important sources of economic and export products in Malaysia. Furthermore, now, the evolution of industry 4.0 has begun to take place globally. The development of sensors has played a role in this evolution. In this paper, various microwave sensors used in oil palm monitoring are reviewed. The advantages and disadvantages of each microwave sensor are discussed in detail. However, conventional and optical monitoring methods are also briefly described.
  • Publication
    Enhanced microwave absorption of rice husk‐based pyramidal microwave absorber with different lossy base layer
    (The Institution of Engineering and Technology, 2020)
    Lee Yeng Seng
    ;
    Soh Ping Jack
    ;
    You Kok Yeow
    ;
    Wee Fwen Hoon
    ;
    Lee Chia Yew
    ;
    Gan Hong Seng
    ;
    Fareq Malek
    The size of pyramidal microwave absorbers (PMA) is one of the main considerations for their selection for use in anechoic chambers. In this work, a new type of PMA is introduced, with rice husk (RH) as its filler. Meanwhile, a lossy base layer is also introduced in the PMA using a combined RH and carbon nanotube (CNT) composite. To do so, the dielectric properties of the RH‐CNT composite are first investigated from 2–18 GHz by using a dielectric probe. Next, the microwave absorption properties of the PMA were investigated in terms of different height of the pyramidal structure and base layer. The free‐space method was used to measure the microwave absorption of PMA at oblique incident angles of 0° to 60°, respectively. Results indicated good microwave absorption characteristics in the 2–6 GHz with a height of 11.5 cm the PMA structure, and 1 cm thickness of the base layer. The lossy base layer is found to increase the bandwidth of the absorber and improve the microwave absorption of PMA in the lower GHz frequencies. Further investigations concluded that the microwave absorption performance of the PMA is dependent on its dielectric properties, size and base layer.
  • 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.
  • Publication
    Design of multiple-layer microwave absorbing structure based on rice husk and carbon nanotubes
    ( 2017-01-01)
    Lee Yeng Seng
    ;
    Wee Fwen Hoon
    ;
    Hasliza A Rahim @ Samsuddin
    ;
    Mohamed Fareq AbdulMalek
    ;
    Kok Yeow You
    ;
    Liyana Zahid
    ;
    Muhammad Ezanuddin Abdul Aziz
    This paper presents a multiple-layered microwave absorber using rice husk and carbon nanotube composite. The dielectric properties of each layer composite were measured and analysed. The different layer of microwave absorber enables to control the microwave absorption performance. The microwave absorption performances are demonstrated through measurements of reflectivity over the frequency range 2–18 GHz. An improvement of microwave absorption <−20 dB is observed with respect to a high lossy composite placed at bottom layer of multiple layers. Reflectivity evaluations indicate that the composites display a great potential application as wideband electromagnetic wave absorbers.
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