Now showing 1 - 10 of 15
  • Publication
    Miniaturized and high gain RFID reader antenna at 13.56MHz
    ( 2020-03-20)
    Saleh Y.M.
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    Yew B.S.
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    Lee Y.S.
    Technology for radio frequency identification (RFID) is commonly used worldwide. RFID is a developing wireless technology which make new vital challenge. The ability to precisely read a set of RFID tags become major concern in RFID networks coverage Detailed analysis of the design based on the 13.56 MHz radio frequency was suggested to design a kind of RFID reader antenna. Previously, researchers did facing problem with the size of the antenna which was to maintain the compact size at low frequency is challenging. The proposed antenna will be designed in the shape of rectangular spiral which contribute into miniaturize of the antenna size. The antenna will be fabricated after the optimum length and width had been achieved. The goal of this project is to design a small size antenna with 55mm 55 mm at frequency resonance of 13.56 MHz. to reduce the antenna gain on the future. We are going to design and add the metamaterial to the RFID reader antenna and combine them together and that will help to reduce the antenna gain.
  • Publication
    Beam controller antenna for WiMAX application
    ( 2017-01-01)
    Leong Lim Wai
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    ;
    Yeow You Kok
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    Mohd Fareq Abdul Malek
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    Yew Lee Chia
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    Seng Lee Yeng
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    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 Co-Planar Waveguide (CPW)-Fed Y-Shaped Patch UWB Antenna for Off-Body Communication
    ( 2020-03-18)
    Kassim S.
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    Soh Ping Jack
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    Abdulmalek M.
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    Jamaluddin M.H.
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    Sabli N.S.
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    Yassin M.N.
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    ; ; ;
    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
    Flexible UWB Compact Circular Split-Ring Slotted Wearable Textile Antenna for Off-Body Millimetre-Wave 5G Mobile Communication
    ( 2020-01-01)
    Lee H.W.
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    Abdulmalek M.
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    Jamaluddin M.H.
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    Mohsin D.A.
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    ; ;
    Yahya N.Z.
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    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.
  • Publication
    Substrate Integrated Waveguide (SIW) coupler on green material substrate for Internet of Things (IoT) applications
    ( 2017-12-11)
    Nurehansafwanah Khalid
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    This 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.
  • Publication
    Potential of Nanocellulose Composite for Electromagnetic Shielding
    ( 2017-12-11)
    Nurul Fatihah Nabila Yah
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    Yeng Seng Lee
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    Mohd Fareq Malek
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    Hayati Hasibuan Zainal
    Nowadays, 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.
  • Publication
    Parametric studies on effects of defected ground structure (DGS) for dual band bandstop microstrip filter
    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) ;
    Yew B.S.
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    ;
    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 RFID Tag Antenna Design
    ( 2020-01-01) ;
    Abdul Malek M.F.
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    Yew B.S.
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    Lee Y.S.
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    Ibrahim S.Z.
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    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
    Design of multiple-layer microwave absorbing structure based on rice husk and carbon nanotubes
    ( 2017-01-01)
    Lee Yeng Seng
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    ; ;
    Mohamed Fareq AbdulMalek
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    Kok Yeow You
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    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.