Now showing 1 - 10 of 34
  • Publication
    A multilayered acoustic signal generator for low power energy harvesting
    This paper presents the design and analysis of a multilayer cantilever to harvest vibration energy by generating acoustic signal. To do so, a five layer configuration is used to design the cantilever. Lead Zirconate Titanate (PZT-8), Stainless Steel 405 Annealed, Aluminum and Zinc Oxide are used to develop the layers. Water is used as the medium to analyze the sound propagation pattern. Sound Pressure Level, displacements and electric potential of the cantilever are analyzed along with other parameters. From the results, it is evident that, the proposed cantilever can propagate sound within a range of 78.7 dB to 73.4 dB in a 50 mm spherical distance.
  • Publication
    Design of Reconfigurable Antenna for RFID System
    ( 2021-07-26)
    Renukka Sivakumar
    ;
    ; ;
    Soh Ping Jack
    ;
    ;
    Salem Al-Bawri S.
    ;
    Jayaprakasam S.
    ;
    ;
    Saluja N.
    This paper proposes a reconfigurable antenna for RFID system which can operate between 860MHz to 960MHz frequency that belongs to ultra-high frequency (UHF) band used in Malaysia with the center frequency of 910MHz. One rectangular slot and two triangle-shaped slots are used in designing this antenna. A good circular polarization obtained from the slotted structure along the diagonal axis in the design. RF pin diodes are used as the switching mechanism of the antenna. However, in this work to proof the concept of switching mechanism, copper pins are used as artificial switches. Parasitic elements are deployed on the right and left side of the driven element to assist the radiation pattern reconfiguration. Overall, the proposed antenna able to steer the beam at approximately at -30 , -16 , and 10 with peak gain of 3.2dB and average gain of 2.5dB. With this result, overall coverage of UHF RFID reader antenna could be improved.
  • 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
    Low loss waveguide-based Butler matrix with iris coupling control method for millimeterwave applications
    ( 2023-01-01)
    Almeshehe M.W.
    ;
    Murad N.A.
    ;
    Rahim M.K.A.
    ;
    Ayop O.
    ;
    Zubir F.
    ;
    Aziz M.Z.A.A.
    ;
    ;
    Majid H.A.
    This paper proposes a low loss 4 × 4 Butler matrix based on rectangular waveguide cavity resonators technology for millimeterwave beamforming network using iris coupling method. This method has the advantage of controlling the electrical fields and the coupling factor inside a complex medium such as waveguide cavity resonators. The coupling factor of 6 dB for 4 × 4 Butler matrix is achieved by tuning the iris coupling k-value between the waveguide cavity resonators. Thus, avoiding a higher phase difference losses and component losses at upper millimeterwave bands. To validate the proposed method, CST software simulations are performed under several iris coupling k-values to achieve a 6 dB coupling factor. Then, the proposed 4 × 4 Butler matrix is 3D metal printed using selective laser melting (SLM) technique. The measured reflection and isolation coefficients are observed below −10 dB, with coupling coefficients ranging between −6 and −7 dB. The phase differences of −42.02°, 42.02°, −130.95°, and 133.3° are achieved at the outputs. It confirmed that using this proposed method has the superiority over the conventional microstrip and waveguide coupling methods by a 1 dB coupling factor loss and a 3° phase difference error.
      1  20
  • Publication
    Design of Compact UHF-RFID Tag Antenna with Meander Line Technique
    In this paper, a compact UHF RFID tag antenna that can operate at Malaysia UHF RFID frequency (860 MHz - 960MHz) is proposed. The antenna with a common geometry structure without any shorting pin consists of 90degree angled line (meander line) and double T-match structure. The proposed antenna has been designed and simulated using CST Simulation software. The proposed tag antenna design shows a good performance in terms of size, gain and impedance with a dimension of 36 mm 25 mm 1.6 mm. The simulated gain of antenna obtained is -0.135 dB at 910 MHz with 19 MHz bandwidth.
      1  26
  • Publication
    Elastomeric polydimethylsiloxane polymer on conductive interdigitated electrode for analyzing skin hydration dynamics
    With an approach towards generating a wearable skin hydration detecting system, simple, cheap, and flexible skin hydration sensing strategy was demonstrated here using an interdigitated electrode (IDE) coated with polydimethylsiloxane (PDMS) matrix. Aluminium IDE with a 400 Âµm gap and 250 Âµm electrode sizes were fabricated using a photolithography method. Morphological characterizations were performed using a high power microscope, 3D-profilometer, and scanning electron microscope. The dimensions of electrodes and gaps measured through electron microscopic analysis affirmed the exactness of IDE and the fabrication process. After coated with PDMS polymer, the IDE/PDMS surface was examined under a high power microscope and 3D-profilometer. The optical characterization revealed the polymer was coated on IDE through the color-shade changes and smooth surface observed under an optical microscope and the respective 3D-visualization. IDE/PDMS was also analyzed by an atomic force microscope, revealing the smoothness of the IDE surface. Electrical characterizations were performed using different pH and urea solutions and the sweat to investigate the influence of real-time and artificial sweat on IDE/PDMS. As the device showed appropriate results with real-time sweat and no effect with artificial interferences, it is highly encouraged and recommended for detecting skin hydration and the related illnesses with the point-of-care concept.
      3  29
  • Publication
    Investigation on the Mutual Coupling Reduction in MIMO Antenna using Dual Split CSRR EBG
    ( 2021-07-26)
    Alsayaghi A.
    ;
    ; ;
    Kabir Hossain
    ;
    ; ;
    Jayaprakasam S.
    ;
    ;
    Raghava N.S.
    In many applications, it is now desirable to prevent a device from being affected by an external electromagnetic field or prevent the device's intrusion into the electromagnetic field. The elimination or reduction of coupling between neighbouring systems is desired, and this is achieved through the use of electromagnetic shields and absorbers. This project focuses on an investigation that analysed the band-gap region for unit cell EBG simulation and unit cell array simulation. It is revealed that unit cell simulation provides an accurate result where the band-gap region is from 2 GHz to 3.5 GHz. The performance of the EBG is validated using a microstrip MIMO antenna. Using EBG, the S21 is reduced from -18.63 dB to -28.80 dB. Meanwhile, the MIMO antenna gain with the proposed EBG is 2.78 dBi, greater than MIMO antenna without EBG (2.47 dBi).
      1  17
  • Publication
    Drunken drive detection with smart ignition lock
    ( 2021-01-01)
    Muthukarpan S.L.A.
    ;
    ; ; ;
    Rahim M.K.A.
    ;
    ;
    Khalib Z.I.A.
    Drink and drive issue have become solemnly that needs immediate attention. This is due to drivers’ ignorance towards road rules and regulations and their selfish attitude that caused loss of innocent lives. Although previously there is a drunk detecting mechanism using breathalyzer but it isn’t suitable for current fast-paced lifestyle. Therefore, to overcome these issues, this system is proposed. This system is fixed on vehicle’s steering to measure alcohol concentration reading using MQ-3 sensor from the driver’s exhaled breath. If the driver found to be drunk beyond the threshold level of 400 ppm, then ignition lock is activated and the car engine does not start till alcohol concentration falls to a safe level. Or, if the driver consumes an alcoholic drink while driving, upon exceeding permissible limit, the car slows down till it stops. Then, the location of the vehicle is tracked and sent as Google Map integrated link via text message to authorized unit. Simultaneously, the car buzzer goes off while the car slows down so that surrounding road users are aware of the driver’s condition and drives at a distance. The proposed detection system is highly potential to be implemented for reducing the drunk and drive accidents.
      1
  • Publication
    Design of a Compact Reconfigurable Antenna with Hybrid Polarization and Frequency Control for Geofencing Application
    A frequency reconfigurable antenna for location monitoring is proposed. The antenna developed can be reconfigured at two frequencies with suitable polarization and radiation pattern which designed for geofencing application, thus it either can operate at 1.575 GHz band or 2.45 GHz band. The expected outcome of this work is that when the user is within the geo-fence area it will use WIFI, while when the user exits the geo-fence area, GPS application will be selected. With the use of two switches, the antenna can operate either at band from 2.335 GHz to 2.593 GHz for S11< -10 dB and from 1.546 GHz to 1.588 GHz at S11 <-6 dB. The axial ratio results of less than 3 dB is achieved at 1.575 GHz with a bandwidth of 20 MHz.
      12  48
  • Publication
    A negative index nonagonal csrr metamaterial-based compact flexible planar monopole antenna for ultrawideband applications using viscose-wool felt
    ( 2021-08-02)
    Kabir Hossain
    ;
    ; ;
    Abdelghany M.A.
    ;
    Soh Ping Jack
    ;
    ; ; ;
    Al-Bawri S.S.
    In this paper, a compact textile ultrawideband (UWB) planar monopole antenna loaded with a metamaterial unit cell array (MTMUCA) structure with epsilon-negative (ENG) and near-zero refractive index (NZRI) properties is proposed. The proposed MTMUCA was constructed based on a combination of a rectangular-and a nonagonal-shaped unit cell. The size of the antenna was 0.825 λ0 × 0.75 λ0 × 0.075 λ0, whereas each MTMUCA was sized at 0.312λ0 × 0.312λ0, with respect to a free space wavelength of 7.5 GHz. The antenna was fabricated using viscose-wool felt due to its strong metal–polymer adhesion. A naturally available polymer, wool, and a human-made poly-mer, viscose, that was derived from regenerated cellulose fiber were used in the manufacturing of the adopted viscose-wool felt. The MTMUCA exhibits the characteristics of ENG, with a bandwidth (BW) of 11.68 GHz and an NZRI BW of 8.5 GHz. The MTMUCA was incorporated on the planar monopole to behave as a shunt LC resonator, and its working principles were described using an equivalent circuit. The results indicate a 10 dB impedance fractional bandwidth of 142% (from 2.55 to 15 GHz) in simulations, and 138.84% (from 2.63 to 14.57 GHz) in measurements obtained by the textile UWB antenna. A peak realized gain of 4.84 dBi and 4.4 dBi was achieved in simulations and measurements, respectively. A satisfactory agreement between simulations and experiments was achieved, indicating the potential of the proposed negative index metamaterial-based antenna for microwave applications.
      1