Ismahayati Adam
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Preferred name
Ismahayati Adam
Official Name
Adam, Ismahayati
Alternative Name
Adam, I.
Ismahayati, A.
Adam, Ismahayati
Main Affiliation
Scopus Author ID
26428028100
Researcher ID
K-7483-2019

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  • Publication
    UWB Antenna with Artificial Magnetic Conductor (AMC) for 5G Applications
    ( 2020-01-01)
    Syuhaimi Kassim
    ;
    Hasliza A Rahim @ Samsuddin
    ;
    Abdulmalek M.
    ;
    R Badlishah Ahmad
    ;
    Jamaluddin M.H.
    ;
    Muzammil Jusoh
    ;
    Mohsin D.A.
    ;
    Yahya N.Z.
    ;
    Wee Fwen Hoon
    ;
    Ismahayati Adam
    ;
    Rani K.N.A.
    This paper presents the design of an ultra-wideband (UWB) antenna for Internet of Things (IoT) applications that operate within 5G operating frequencies. One of the IoT-based devices’ architecture is wireless body area networks (WBANs). WBAN allows computer device to communicate with human body signal by trading digital information like electrical conductivity. Fifth generation (5G) is the state-of-the-art generation mobile communication. A higher data speed it offers will improve data communication efficiency in WBAN system. One of the biggest challenges foreseen for the wearable UWB antenna is the antenna bandwidth. The challenge is to warrant a wideband performance throughout the operating frequency, and a trade-off with a high dielectric in proposed substrate is essential. This paper presents design and parametric analysis of an antenna using a typical industry-preferred Rogers material (RO4350B) substrate with wider bandwidth as compared to 5G frequencies, 10.125–10.225 GHz. This paper also exhibits bandwidth improvement with the presence of artificial magnetic conductor (AMC) as a metasurface. A typical UWB patch antenna was initially designed before being integrated with AMC through a parametric analysis. This paper analyzes the frequency, gain, directivity and antenna efficiency before and after optimization. This paper successfully demonstrates a slotted Y-shaped antenna design with coplanar waveguide (CPW) using a Rogers material (RO4350B) as a substrate and the bandwidth improvement by 15.6% with the AMC as a metasurface.
  • Publication
    Bending Assessment of Dual-band Split Ring-shaped and Bar Slotted All-Textile Antenna for Off-body WBAN/WLAN and 5G Applications
    ( 2020-09-28)
    Mashaghba H.A.
    ;
    Hasliza A Rahim @ Samsuddin
    ;
    Soh Ping Jack
    ;
    Abdulmalek M.
    ;
    Ismahayati Adam
    ;
    Muzammil Jusoh
    ;
    Thennarasan Sabapathy
    ;
    Mohd Najib Mohd Yasin
    ;
    Khairul Najmy Abdul Rani
    This paper presents a dual-band split ring-shaped and bar slotted textile antenna for potential WBAN/WLAN and 5G applications. The antenna is made using textiles and features a full ground plane to possibly alleviate coupling to the human body. The overall size of the antenna is 70 x 70 mm2, with a patch sized at 47.2 x 31 mm2 0.472 \lambda \times 0.031 \lambda. The antenna is made using ShieldIt Super as its conductive textile and felt as its substrate. To enable its dual-band resonance at 2.45 and 3.5 GHz a split ring-shaped and bar slots are integrated onto the patch. The proposed antenna is evaluated when bent under different radii and at different axes to estimate its performance in terms of reflection coefficient, bandwidth, efficiency and gain. A 10-dB impedance bandwidth of 57 % or 135 MHz (from 2.39 to 2.52 GHz) and 70 % or 240 MHz (from 3.45 to 3.56 GHz) are obtained when evaluated in the planar /bent configuration. The maximum realized gain is 6 dBi for at 3.5 GHz. These performances indicate that the antenna proposed in this work can be potentially improved for applications in WBAN/WLAN and 5G bands.
  • 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.
    ;
    Hasliza A Rahim @ Samsuddin
    ;
    Abdulmalek M.
    ;
    R Badlishah Ahmad
    ;
    Jamaluddin M.H.
    ;
    Muzammil Jusoh
    ;
    Mohsin D.A.
    ;
    Wee Fwen Hoon
    ;
    Ismahayati Adam
    ;
    Yahya N.Z.
    ;
    Khairul Najmy Abdul Rani
    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
    A Comprehensive Review of Midrange Wireless Power Transfer Using Dielectric Resonators
    ( 2021-01-01)
    Azuwa Ali
    ;
    Mohd Najib Mohd Yasin
    ;
    Faiz Wan Ali W.F.
    ;
    Norsuria Mahmed
    ;
    Kamarudin M.R.
    ;
    Ismahayati Adam
    ;
    Muzammil Jusoh
    ;
    Hasliza A Rahim @ Samsuddin
    ;
    Khor Shing Fhan
    ;
    Nurulazlina Ramli
    ;
    Norshamsuri Ali @ Hasim
    Magnetic resonant coupling (MRC) is one of the techniques that are widely used in wireless power transfer (WPT) systems. The technique is commonly used for enhancing distance while maintaining power transfer efficiency (PTE). Many studies have investigated new technologies to extend the distance of MRC while maintaining high PTE values. The most promising technique to date in MRC is the addition of a resonator between the transmitter and the receiver coil. The implementation of the resonator varies based on different designs, sizes, and material types, although the outcomes remain unsatisfactory. By introducing dielectric material resonators, PTE can be improved by lowering the ohmic loss which becomes a problem on conventional resonators. This study presents a general overview on the use of dielectric material as a resonator in MRC WPT technology and its technological development. The basic operation of MRC WPT is summarized with up-to-date technical improvements related to dielectric material as a resonator in the field of WPT. An overview of the current limitations and challenges of this technique is also highlighted in this study.
      1
  • Publication
    1×4 Patch Array All-Textile Antenna for WLAN Applications
    ( 2020-09-28)
    Mashaghba H.A.
    ;
    Hasliza A Rahim @ Samsuddin
    ;
    Ping Jack Soh
    ;
    Abdulmalek Mohamedfareq
    ;
    Ismahayati Adam
    ;
    Muzammil Jusoh
    ;
    Mohd Najib Mohd Yasin
    ;
    Thennarasan Sabapathy
    ;
    Khairul Najmy Abdul Rani
    This paper proposes the design of 1×4 patch array all-Textile antenna for Wireless Local Area Networks (WLAN) applications. The wearable antenna needs to have low profile and lightweight since such antenna is intended to operate in the vicinity of the human body. The key parameters are studied to determine their effects towards the performance of the antenna. The proposed design uses ShieldIt as the top radiator and ground plane, while fabric Felt is used as a substrate, sandwiched between the top radiator and ground plane.The obtained results show that there is improvement in the proposed array antenna in terms of gain enhancement and impedance bandwidth, maximum up to 143.6% and 19.08%, respectively, against single patch structure.
      9  2
  • Publication
    Investigation on Wearable Antenna under Different Bending Conditions for Wireless Body Area Network (WBAN) Applications
    ( 2021-01-01)
    Ismahayati Adam
    ;
    Kamarudin M.R.
    ;
    Rambe A.H.
    ;
    Haris N.
    ;
    Hasliza A Rahim @ Samsuddin
    ;
    Wan Zuki Azman Wan Muhamad
    ;
    Arif Mawardi Ismail
    ;
    Muzammil Jusoh
    ;
    Mohd Najib Mohd Yasin
    This paper analysed the effects of bending on the performance of a textile antenna wherein the antenna under test was made of felt substrate for both industrial, scientific, and medical (ISM) band and WBAN applications at 2.45 GHz. Moreover, the conductive material was used for the patch, and the ground plane used a 0.17 mm Shieldit textile. Meanwhile, the antenna structure was in the form of rectangular, with a line patch in between elements to abate the mutual coupling effect. The measured operating frequency range of the antenna spanned from 2.33 GHz to 2.5 GHz with a gain of 4.7 dBi at 2.45 GHz. In this paper, the antenna robustness was examined by bending the structure on different radii and degrees along both X- and Y-axis. Next, the effects on return loss, bandwidth, isolation, and radiation characteristics were analysed. This paper also discovered that the antenna's performance remained acceptable as it was deformed, and the measured results agreed well with the simulation.
      1
  • Publication
    A Hybrid Mutual Coupling Reduction Technique in a Dual-Band MIMO Textile Antenna for WBAN and 5G Applications
    ( 2021-01-01)
    Hamza A. Mashagba
    ;
    Hasliza A Rahim @ Samsuddin
    ;
    Ismahayati Adam
    ;
    Jamaluddin M.H.
    ;
    Mohd Najib Mohd Yasin
    ;
    Muzammil Jusoh
    ;
    Thennarasan Sabapathy
    ;
    Abdulmalek M.
    ;
    Azremi Abdullah Al-Hadi
    ;
    Arif Mawardi Ismail
    ;
    Soh Ping Jack
    This paper presents a hybrid mutual coupling reduction technique applied onto a dual-band textile MIMO antenna for wireless body area network and 5G applications. The MIMO antenna consists of two hexagonal patch antennas, each integrated with a split-ring (SR) and a bar slot to operate in dual-band mode at 2.45 GHz and 3.5 GHz. Each patch is dimensioned at 47.2 × 31 mm2. This hybrid technique results in a simple structure, while enabling significant reduction of mutual coupling (MC) between the closely spaced patches (up to 0.1 λ). This technique combines a line patch and a patch rotation technique, explained as follows. First, a line patch is introduced at an optimized distance to enable operation with a broad impedance bandwidth at both target frequencies. One of the patches is then rotated by 90° at an optimized distance, resulting in a significant MC suppression while maintaining the dual and broad impedance bandwidth. The proposed MIMO antenna is further evaluated under several bending configurations to assess its robustness. A satisfactory agreement between simulated and measured results is observed in both planar and bending conditions. Results show that the MIMO antenna achieves an impedance bandwidth of 4.3 % and 6.79 % in the 2.45 GHz and 3.5 GHz band, respectively. Moreover, very low MC (S21 <-30 dB) is achieved, with a low (< 0.002) envelop correlation coefficient, and about 10 dB of diversity gain at both desired frequencies using this technique. Even when bent at an angle of 50° at the x-and y-axes, the antenna bent maintained a realized gain of 1.878 dBi and 4.027 dBi in the lower and upper band, respectively. A robust performance is offered by the antenna against the lossy effects of the human body with good agreements between simulated and measured results.
      1
  • Publication
    5G Millimeter Wave Wearable Antenna: State-Of-the-Art and Current Challenges
    ( 2021-01-01)
    Hasliza A Rahim @ Samsuddin
    ;
    Mashagba H.A.
    ;
    Yahaya N.Z.
    ;
    Mohd Najib Mohd Yasin
    ;
    Jamaluddin M.H.
    ;
    Muzammil Jusoh
    ;
    Thennarasan Sabapathy
    ;
    Ismahayati Adam
    ;
    Abdulmalek M.
    Fifth Generation (5G) is the next evolution of mobile communication that will provide seamless and massive high speed connectivity to the society. Paralleled with the rise of 5G, it is foreseen that wearable devices particularly wearable antenna will be the significant end node for wearable devices in Millimeter Wave (mmWave) frequency bands. Thus, this paper discusses the new development of the 5G sub-6 GHz and mmWave wearable antenna, introduces the research results of the 5G mmWave wearable antenna in recent years, and addresses the key challenges in the development trend of the development trend of the 5G mmWave wearable antenna.
      1