Now showing 1 - 8 of 8
  • Publication
    Performance enhancement of semicircular shaped array antenna using metasurface
    (Institute of Electrical and Electronics Engineers (IEEE), 2020)
    H. Lago
    ;
    M. Faizal Jamlos
    ;
    A. Narbudowicz
    ;
    Soh Ping Jack
    ;
    A. R. Haron
    ;
    ;
    M. H. Limbah
    This work studies the integration of a semicircular shaped array antenna into an Artificial Magnetic Conductor (AMC) which resonate at the desired operating frequency of 9.41 GHz. The proposed AMC performs as a high impedance surface with a high permeability (approximately 7.08) at 9.41 GHz, with a perfect magnetic conductor characteristic. As result, the AMC is able to be stacked adjacent to the semicircular shaped. The simulation results show that the AMC has successfully enhanced the gain and efficiency of the antenna to 9.55 dB and 97% respectively compared to 8.44 dB and 96% without AMC. Besides that, a slight bandwidth improvement, from 395 MHz to 398 MHz can be observed with the AMC. Both simulated and measured results show a good agreement in term of reflection coefficients and radiation patterns.
  • 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
    The design evolution of trio-band vivaldi antenna with meander-line-fed shape for ground penetrating radar application
    (IEEE, 2024-01)
    Mohd Syahir Ahmad Azhari
    ;
    ;
    Mimi Diana Ghazali
    ;
    ;
    Ainur Fasihah Mohd Fazilah
    This paper is proposed based on considerable reviewed design techniques. It works at 200MHz, 800MHz and 1,200MHz named as “Trio-Band” with the fixed size of 300mm×300mm×1.6mm of the FR4 substrate. The antenna application is for Ground Penetrating Radar (GPR) with targeted depth range is from 10cm to 1,000cm. The combination of slotted shapes which is Half-circle, Staircase, Quarter-eclipse and Circular-Ring are applied to achieve the Trio-Band with the parametric analysis to determine the appropriate size. The final Vivaldi antenna achieves the reflective coefficient (S11) with -30.05dB (200MHz), -12.05dB (800MHz) and -15.35dB (1,200MHz) as well as 50Ω of impedance matching.
  • Publication
    A triband wearable antenna for location tracking using cospas-sarsat and GNSS
    (IEEE, 2025)
    Rais Ahmad Sheikh
    ;
    ;
    Roy B. V. B. Simorangkir
    ;
    ;
    Rizwan Khan
    ;
    Prayoot Akkaraekthalin
    ;
    Surentiran Padmanathan
    ;
    Toufiq Md Hossain
    ;
    ;
    Ping Jack Soh
    This paper presents the design of a tri-band antenna operating in the Cospas-Sarsat (C-S) and GPS/GNSS bands applicable for the Internet of Things (IoT). Implemented with flexible and robust materials, the antenna operates in three distinct frequencies: 406 MHz for C-S applications and 1227 MHz (L2) and 1575 MHz (L1) for GPS/GNSS applications. The measured 10-dB impedance bandwidth is from 1.517-1.587 MHz (in L1 band) and from 1.192-1.232 MHz (in L2 band). In C-S band, the measured 6-dB bandwidth is from 393 to 406.5 MHz. The 3 dB axial ratio (AR) bandwidth in the L1 and L2 bands are 17 MHz (1.08%) and 18 MHz (1.47%), respectively. The antenna demonstrates a measured gain of 1.61 dB at 406 MHz, exceeding the simulated gain of 0.573 dB, and features a beamwidth of 140°. The measured gains for the L2 and L1 bands closely align with the simulations, although a slight reduction in gain is observed for the L2 band. In the H-plane, zenith-directed main lobes produce measured gains of 1.61 dB for 406 MHz, 2.71 dB for L2, and 3.51 dB for L1. On the other hand, the measured efficiency for the antenna is 36.32% (in the C-S band), 54% (in L1 band) and 60.12% (in L2 band). Both measured and simulated results consistently showed good agreements in terms of gain, polarization, and efficiency. Moreover, the antenna design incorporates effective shielding against electromagnetic radiation, conforming to specific absorption rate (SAR) values of 0.046, 0.077, and 0.035 W/Kg in C-S, L1 and L2 bands respectively. Antenna integration into the life vest foam prior to placement on the human chest significantly influenced axial ratio variations. In the L1 band, the AR increased from 0.43 dB to 3.34 dB, while in the L2 band, it rose from 0.56 dB to 8.66 dB. This indicates a more pronounced effect on polarization characteristics at the lower frequency. Overall, the proposed tri-band antenna presents promising capabilities for location tracking applications, with potential for integration into wearable devices for enhanced safety and tracking functionalities.
  • 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
    Compact full flexible vivaldi antenna for 3.5 GHz wearable applications
    (IEEE, 2023)
    Bikash Chandra Sahoo
    ;
    ; ; ;
    Surentiran Padmanathan
    ;
    Sadia Afroz
    ;
    ;
    Yen San Loh
    ;
    Muhammad Syahir Mahyuddin
    ;
    Lai Ming Lim
    ;
    Zambri Samsudin
    ;
    Idris Mansor
    ;
    Soh Ping Jack
    In this paper, a compact wearable Vivaldi antenna resonating at 3.5 GHz is proposed for 5G n77, and n78 bands. It is designed upon a flexible polyester substrate having dielectric constant (εr) of 1.34 and loss tangent (tan δ) of 0.005. The antenna parameters were optimized via parametric analyses using CST software with a size of 45 × 45 × 0.4 mm3 (length × width × height). The antenna is evaluated in terms of reflection coefficient, gain, efficiency, radiation pattern, and surface current density. This antenna attained a maximum simulated gain of 4.7 dBi, and an efficiency of 98 % in the resonating band.
      7  1
  • Publication
    Feasibility study on embroidered Wi-Fi antenna performances
    Performance of a dual-band coplanar patch antenna with bending and wet condition is described in this paper. The antenna structure is made from common clothing fabrics and operates at the 2.45 and 5 GHz wireless bands. The antenna's radiating element is using Nora Dell serves as a ground plane and Felt as the substrate. The final part carries out the simulation on forward, backward bending, and also the wet condition in CST software. The comparison of two bending conditions is discussed in this report.
      21  3
  • Publication
    Comparison Study of UHF Sensor Modelling Based on 4th Order Hilbert Fractal Category for Partial Discharge Detection in Power Transformer
    PD detection is an effective method of inspecting insulation defects and identifying potential faults in a power transformer. Electromagnetic waves generated due to PD can be detected by ultrahigh-frequency (UHF) sensor in the frequency band greater than 300 MHz. However, the size and the frequency bandwidth of a UHF sensor for PD detection are the concern for practical installation inside a transformer. High sensitivity and wide bandwidth of sensors are needed in order to detect the PD signal at an early stage. This paper presents an array with partial ground 4th order Hilbert fractal UHF sensor for PD detection inside a power transformer. This UHF sensor was modeled to capture PD signal in a range of frequencies between 300 MHz to 3 GHz. The sensor is designed by using CST software where the transmission lines combined 2 sensors become 1 output by setting the dimension of 100 x 200 mm for length and width with an FR4 epoxy substrate of thickness 1.6 mm. Based on the simulation result, the proposed sensor is obtained a PD signal measurement with a reflection coefficient below-10 dB with VSWR ?5. The advantages of this sensor have a wide bandwidth, high sensitivity and suitable size for easy installation. Thus, this sensor has been qualified as UHF PD detection in the power transformer.
      5  28