Now showing 1 - 10 of 23
  • 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
    Flexible 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).
  • Publication
    Beam controller antenna for WiMAX application
    ( 2017-01-01)
    Leong Lim Wai
    ;
    ;
    Yeow You Kok
    ;
    Mohd Fareq Abdul Malek
    ;
    Yew Lee Chia
    ;
    Seng Lee Yeng
    ;
    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
    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
    ;
    ;
    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
    An ultrawideband full flexible 4 elements DGS based MIMO antenna for Sub-6 GHz wearable applications
    (IEEE, 2024-03)
    Bikash Chandra Sahoo
    ;
    ; ;
    Surentiran Padmanathan
    ;
    Sadia Afroz
    ;
    ;
    Soh Ping Jack
    ;
    ;
    Soumya Ranjan Mishra
    In this article, a compact wearable quad element MIMO antenna is presented operating at 4.5 GHz for 5G n77, n78, and n79 bands with the use of polyester substrate with a size of 80 × 82 × 0.4 mm3. Here T-shaped defected ground structure (DGS) technique has been utilized to improve the impedance bandwidth along with the reduction of the mutual coupling between the radiating elements. The antenna is evaluated in terms of reflection coefficient, gain, efficiency, and radiation pattern. The proposed MIMO antenna attained a maximum simulated gain of 4.3 dBi, and an efficiency of 96 % in the resonating band.
  • Publication
    Flexible RFID Tag Antenna Design
    ( 2020-01-01) ;
    Abdul Malek M.F.
    ;
    Yew B.S.
    ;
    Lee Y.S.
    ;
    Ibrahim S.Z.
    ;
    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.
      17  1
  • Publication
    Miniaturized and high gain RFID reader antenna at 13.56MHz
    ( 2020-03-20)
    Saleh Y.M.
    ;
    ;
    Yew B.S.
    ;
    ;
    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.
      4  18
  • Publication
    A 3.5 GHz wearable antipodal vivaldi antenna for 5G applications
    (IEEE, 2024-01)
    Sadia Afroz
    ;
    ;
    Surentiran Padmanathan
    ;
    ; ;
    Bikash Chandra Sahoo
    ;
    Yen San Loh
    ;
    ;
    Lun Hao Tung
    ;
    Lai Ming Lim
    ;
    Zambri Samsudin
    ;
    Idris Mansor
    ;
    Soh Ping Jack
    This paper represents a wideband wearable antenna for 5G applications. In this proposed design, an antipodal vivaldi antenna structure is implemented on a polyimide and polyester combined substrate. The 120 × 95 × 0.82 mm3 sized antenna acquired a wide bandwidth of 910 MHz with a realized gain of 5.42 dBi and efficiency of 96 percent.
      10  2
  • Publication
    Design of multiple-layer microwave absorbing structure based on rice husk and carbon nanotubes
    ( 2017-01-01)
    Lee Yeng Seng
    ;
    ; ;
    Mohamed Fareq AbdulMalek
    ;
    Kok Yeow You
    ;
    ;
    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.
      4  31
  • Publication
    Substrate Integrated Waveguide (SIW) coupler on green material substrate for Internet of Things (IoT) applications
    ( 2017-12-11)
    Nurehansafwanah Khalid
    ;
    ;
    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.
      2  20