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Wee Fwen Hoon
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
Now showing
1 - 10 of 15
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PublicationDesign of Ultra-Wideband Monopole Antenna for EMC Application( 2023-10-06)
;Yew B.S.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. -
PublicationDesign of multiple-layer microwave absorbing structure based on rice husk and carbon nanotubes( 2017-01-01)
;Lee Yeng Seng ;Mohamed Fareq AbdulMalek ;Kok Yeow YouMuhammad Ezanuddin Abdul AzizThis 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. -
PublicationFlexible Co-Planar Waveguide (CPW)-Fed Y-Shaped Patch UWB Antenna for Off-Body Communication( 2020-03-18)
;Kassim S. ;Soh Ping Jack ;Abdulmalek M. ;Jamaluddin M.H. ;Sabli N.S. ;Yassin M.N.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). -
PublicationPotential of Nanocellulose Composite for Electromagnetic Shielding( 2017-12-11)
;Nurul Fatihah Nabila Yah ;Yeng Seng Lee ;Mohd Fareq MalekHayati Hasibuan ZainalNowadays, most people rely on the electronic devices for work, communicating with friends and family, school and personal enjoyment. As a result, more new equipment or devices operates in higher frequency were rapidly developed to accommodate the consumers need. However, the demand of using wireless technology and higher frequency in new devices also brings the need to shield the unwanted electromagnetic signals from those devices for both proper operation and human health concerns. This paper highlights the potential of nanocellulose for electromagnetic shielding using the organic environmental nanocellulose composite materials. In addition, the theory of electromagnetic shielding and recent development of green and organic material in electromagnetic shielding application has also been reviewed in this paper. The use of the natural fibers which is nanocelllose instead of traditional reinforcement materials provides several advantages including the natural fibers are renewable, abundant and low cost. Furthermore, added with other advantages such as lightweight and high electromagnetic shielding ability, nanocellulose has a great potential as an alternative material for electromagnetic shielding application. -
PublicationParametric studies on effects of defected ground structure (DGS) for dual band bandstop microstrip filter( 2017-11-22)
;Farah Shazuani MahmudA 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. -
PublicationFlexible UWB Compact Circular Split-Ring Slotted Wearable Textile Antenna for Off-Body Millimetre-Wave 5G Mobile Communication( 2020-01-01)
;Lee H.W. ;Abdulmalek M. ;Jamaluddin M.H. ;Mohsin D.A. ;Yahya N.Z.A flexible ultra-wideband (UWB) compact circular split-ring slotted wearable textile antenna for off-body 28 GHz fifth-generation (5G) mobile communication is proposed. The proposed antenna is implemented using low-cost felt textile substrates and copper. The proposed 5G wearable antenna of compact circular split-ring slotted with enhanced bandwidth of 0.5% with the resonance frequency of 28 GHz is presented. The S11 for patch antenna with slot exhibited 43.4% more than the patch antenna without slot. The results also exhibited that the bending angle of 10° and 20° perform better return loss than in flat condition, up to 14% for patch antenna with slot against without the slot. -
PublicationSubstrate Integrated Waveguide (SIW) coupler on green material substrate for Internet of Things (IoT) applications( 2017-12-11)
;Nurehansafwanah KhalidThis paper shows designed coupler on paper-substrate with Substrate Integrated Waveguide (SIW) techniques. Types of paper-substrate that used are photographic paper. The rectangular coupler is presented with Substrate Integrated Waveguide (SIW) which metallic via on paper-substrate. The structures of the coupler are designed and analysed using Computer Simulation Tools (CST) Studio Suite 2014 Software. This designed coupler operating within frequency of 3.8-5 GHz. The paper-based substrates are permits the implementation of green materials (Eco-friendly) technology. The design of the coupler and its simulated results are reported in this paper. -
PublicationAnalysis of Dielectric Properties on Agricultural Waste for Microwave Communication Application( 2017-12-11)
;Nurul Ain Zulkifli ;Been Seok Yew ;Yeng Seng LeeAnusha Leemsuthep Am PhanThis 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. -
PublicationTuneable dual-mode narrowband bandstop filter using loaded microstrip resonator( 2017-01-03)
;Farah Shazuani MahmudNovel tuneable dual-mode narrowband bandstop filter using loaded microstrip resonator is presented. The filter is designed by using coupled line coupling with the microstrip resonator. There is two different pair of loaded resonator that produces a dual band bandstop filter. The dual band bandstop resonance frequency can be tuned independently by adjusting the resonator width and length. To achieve high selectivity of the bandstop filter response, defected ground structure (DGS) is applied in the filter layout. The tapped lines structure (TLS) are used to suppress second harmonic frequency. The dual band bandstop filter is resonant at 2.4 GHz with 200 MHz of bandwidth and 5.8 GHz with 300 MHz of bandwidth. The bandstop filter layout is fabricated on RO 4003C with 0.508 mm of substrate thickness. It is compact dimension with 19.6mm × 38.8mm. The advantages of this bandstop filter are simple layout and it can be tuned to the specified frequencies. -
PublicationSubstrate integrated waveguide (SIW) 3 dB coupler for K-Band applications( 2017-11-22)
;Nurehansafwanah KhalidFarah Shazuani MahmudThis paper presented a designed coupler by using Rogers RO4003C with thickness (h) 0.508 mm and relative permittivity (ϵr) 3.55. The four port network coupler operates in K-band (18-27 GHz) and design by using substrate integrated waveguide (SIW) method. The reflection coefficient and isolation coefficient of propose Substrate Integrated Waveguide (SIW) coupler is below than -10 dB. Meanwhile the coupler requirements are phase shift 90° between coupled port and output. SIW are high performance broadband interconnects with excellent immunity to electromagnetic interference and suitable for use in microwave and communication electronics, as well as increase bandwidth systems. The designs of coupler are investigated using CST Microwave Studio simulation tool. This proposed couplers are varied from parameters that cover the frequency range (21 -24 GHz) and better performance of scattering (S-parameter).