Mohd Najib Mohd Yasin
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Mohd Najib Mohd Yasin
Official Name
Mohd Najib , Mohd Yasin
Alternative Name
M. Yasin, M. Najib
Yasin, Mohd Najib
Yasin, Mohd Najib M.
Yasin, M. N.Mohd
Mohd Yasin, M. N.
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Scopus Author ID
57210314287
Researcher ID
AAQ-6242-2021

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  • Publication
    Size-Reduction of a Dual-Band Circularly Polarized Dielectric Resonator Antennas
    ( 2021-01-01)
    Mohd Najib Mohd Yasin
    ;
    Ali A.
    ;
    Zambak M.F.
    ;
    Radzi M.F.
    In this paper, a circularly polarized rectangular DRA has been designed and simulated for WiMAX, satellite, 5G NR band applications. The design uses an F-shaped conducting patch with a parasitic patch to excite the design. The bandwidth enhancement of the design has been achieved thorough the optimization of the patch placement and gap distance for both conducting patch and parasitic patch to cover the desired operating frequency. The S11<10 dB and axial ratio< -3 dB result covers the operating frequency range. The designing and optimization of the design has been carried out using the CST Studio Suite software.
  • Publication
    Essential semiconductor films in micro-/nano-biosensors: Current scenarios
    ( 2021-10-01)
    Subash Chandra Bose Gopinath
    ;
    Ramanathan S.
    ;
    Mohd Najib Mohd Yasin
    ;
    Shapiai M.I.
    ;
    Ismail Z.H.
    ;
    Subramaniam S.
    Background: Engineering nanoscale matter in a controlled functional system has expanded the area of science in the state-of-art of nanotechnology. The urgency in introducing real-time health monitoring sensors and rapid diagnostic tools in medical health is indeed high and crucial to date. The efforts are accompanied by nanotechnology to improve the sensors performances. In this line, semiconductor materials (Silicon/Silica) have been in well-focus to develop micro-/nano-sensors. Methods: Further, additional layering such as metal oxide and graphene material have elevated the current scenario in biosensor developments. Among these, two-dimensional graphene nanomaterial owns its remarkable mechanical, electronic, electrochemical, and optical properties, has excited the medical field to develop graphene-based biosensors for human health diagnosis and monitoring. The oxygen rich graphene materials enhance the bio-functionalization of recognition bio-elements for excellent graphene-based biosensor development. Significance: This review encloses the excellence of semiconductor materials in conjunction with biosensors for monitoring health and diagnosis. The advances and challenges encountered with developing semiconductors for nanobiosensors from laboratory set-up to the novel hand-held device for rapid and accurate human health care are outlined.
  • Publication
    Orbital Angular Momentum Vortex Waves Generation Using Textile Antenna Array for 5G Wearable Applications
    ( 2022-01-01)
    Noor S.K.
    ;
    Mawardi Ismail A.
    ;
    Mohd Najib Mohd Yasin
    ;
    Mohamed Nasrun Osman
    ;
    Ramli N.
    The development of wireless systems for fifth-generation technology (5G) has enabled the use of textile antennas for a wide range of applications, and it has now become one of the world's most in-demand technology. As the number of wireless devices and users increase, operators would need higher channel capacity to deliver better possible service to their customers. This paper presents the generation of Orbital Angular Momentum (OAM) vortex waves with mode 1 using a wearable textile antenna. OAM introduces a new scheme called Mode Domain Multiple Access (MDMA). OAM mode is an orthogonal mode with each mode carrying individual signals. Therefore, multiple signals can be sent using the same carrier frequency without additional resources. This allows the channel capacity and spectrum efficiency to be enhanced. The proposed antenna array comprises rectangular microstrip patch elements with an inset fed technique. Felt textile fabric was used as an antenna substrate. A carefully planned feeding phase shift network was used to excite the elements by supplying similar output energy at output ports with the required phase shift value. The generated OAM waves were confirmed by measuring the null in the boresight direction of their 2D radiation patterns as well as simulated phase distribution, intensity distribution and mode purity. The antenna covered portions of the 5G n77 band with a bandwidth of 81.7 MHz and an overall gain of 2.9 dBi. This is, to the best of our knowledge, the first work on generating OAM waves using a flexible textile material.
  • Publication
    A Review of Circularly Polarized Dielectric Resonator Antennas: Recent Developments and Applications
    ( 2022-12-01)
    Abd Rahman N.A.
    ;
    Mohd Najib Mohd Yasin
    ;
    Ibrahim I.M.
    ;
    Muzammil Jusoh
    ;
    Noor S.K.
    ;
    Ekscalin Emalda Mary M.R.
    ;
    Zamin N.
    ;
    Nurhayati N.
    A comprehensive review on recent developments and applications of circularly polarized (CP) dielectric resonator antennas (DRAs) is proposed in this paper. DRAs have received more considerations in various applications due to their advantages such as wide bandwidth, high gain, high efficiency, low losses, and low profile. A broad justification for circular polarization and DRAs is stated at the beginning of the review. Various techniques such as single feed, dual, or multiple feeds used by different researchers for generating circular polarization in DRAs are briefly studied in this paper. Multiple-input-multiple-output (MIMO) CP DRAs, which can increase channel capacity, link reliability, and data rate, have also been analyzed. Additionally, innovative design solutions for broadening the circular polarization bandwidth and reducing mutual coupling are studied. Several applications of DRA are also discussed comprehensively. This paper finishes with concluding remarks.
  • Publication
    The design of wideband circularly polarized hemispherical DRA using conformal open halfloop excitation
    ( 2017-12-15)
    Mohamad Ismail Sulaiman
    ;
    Mohd Najib Mohd Yasin
    ;
    Hafiz Basarudin
    ;
    Aizat Faiz Ramli
    ;
    Mohd Azlan Abu
    A circularly polarized (CP) hollow hemispherical dielectric resonator antenna (DRA) is presented. The CP DRA that is excited using conformal open half loop metal strips has been studied theoretically and experimentally. The proposed antenna configuration has provided a measured CP and return loss bandwidths of ∼11.i5%, and 10.32% respectively. The DRA has been simulated using Method of Moments (MoM) model, where a good agreement has been obtained between the experimental and theoretical results.
  • Publication
    Modeling superconducting critical temperature of 122-iron-based pnictide intermetallic superconductor using a hybrid intelligent computational method
    ( 2021-08-02)
    Akomolafe O.
    ;
    Owolabi T.O.
    ;
    Rahman M.A.A.
    ;
    Kechik M.M.A.
    ;
    Mohd Najib Mohd Yasin
    ;
    Souiyah M.
    Structural transformation and magnetic ordering interplays for emergence as well as suppression of superconductivity in 122-iron-based superconducting materials. Electron and hole doping play a vital role in structural transition and magnetism suppression and ultimately enhance the room pressure superconducting critical temperature of the compound. This work models the superconducting critical temperature of 122-iron-based superconductor using tetragonal to orthorhombic lattice (LAT) structural transformation during low-temperature cooling and ionic radii of the dopants as descriptors through hybridization of support vector regression (SVR) intelligent algorithm with particle swarm (PS) parameter optimization method. The developed PS-SVR-RAD model, which utilizes ionic radii (RAD) and the concentrations of dopants as descriptors, shows better performance over the developed PS-SVR-LAT model that employs lattice parameters emanated from structural transformation as descriptors. Using the root mean square error (RMSE), coefficient of correlation (CC) and mean absolute error as performance measuring criteria, the developed PS-SVR-RAD model performs better than the PS-SVR-LAT model with performance improvement of 15.28, 7.62 and 72.12%, on the basis of RMSE, CC and Mean Absolute Error (MAE), respectively. Among the merits of the developed PS-SVR-RAD model over the PS-SVR-LAT model is the possibility of electrons and holes doping from four different dopants, better performance and ease of model development at relatively low cost since the descriptors are easily fetched ionic radii. The developed intelligent models in this work would definitely facilitate quick and precise determination of critical transition temperature of 122-iron-based superconductor for desired applications at low cost with experimental stress circumvention.
  • Publication
    Critical Review: Adaptive Pole Assignment PID Controller on DC-DC Converters
    ( 2020-03-20)
    Husna A.W.N.
    ;
    Mohd Hafizuddin Mat
    ;
    Mohd Najib Mohd Yasin
    ;
    Muzammil Jusoh
    ;
    Mohd Irwan Yusoff
    ;
    Mohamad Shukor Abdul Rahim
    ;
    Esa S.M.
    Recently, control usages of DC-DC converters have been widely investigated particularly in renewable energy; as the primary sources. Discovering the most appropriate control method to be applied in DC-DC converter topologies is the most significant interest of research and development in this field. Thus, the review is carried out in selecting a control method that capable to improve the functioning of the converters as well as reducing the effect of disturbances and load variances.
  • Publication
    Multi-stage feature selection (MSFS) algorithm for UWB-based early breast cancer size prediction
    ( 2020-08-01)
    Vijayasarveswari V.
    ;
    Allan Melvin Andrew
    ;
    Muzammil Jusoh
    ;
    Thennarasan Sabapathy
    ;
    Rafikha Aliana A Raof
    ;
    Mohd Najib Mohd Yasin
    ;
    R Badlishah Ahmad
    ;
    Khatun S.
    ;
    Hasliza A Rahim @ Samsuddin
    Breast cancer is the most common cancer among women and it is one of the main causes of death for women worldwide. To attain an optimum medical treatment for breast cancer, an early breast cancer detection is crucial. This paper proposes a multistage feature selection method that extracts statistically significant features for breast cancer size detection using proposed data normalization techniques. Ultra-wideband (UWB) signals, controlled using microcontroller are transmitted via an antenna from one end of the breast phantom and are received on the other end. These ultra-wideband analogue signals are represented in both time and frequency domain. The preprocessed digital data is passed to the proposed multistage feature selection algorithm. This algorithm has four selection stages. It comprises of data normalization methods, feature extraction, data dimensional reduction and feature fusion. The output data is fused together to form the proposed datasets, namely, 8-HybridFeature, 9-HybridFeature and 10-HybridFeature datasets. The classification performance of these datasets is tested using the Support Vector Machine, Probabilistic Neural Network and Naïve Bayes classifiers for breast cancer size classification. The research findings indicate that the 8-HybridFeature dataset performs better in comparison to the other two datasets. For the 8-HybridFeature dataset, the Naïve Bayes classifier (91.98%) outperformed the Support Vector Machine (90.44%) and Probabilistic Neural Network (80.05%) classifiers in terms of classification accuracy. The finalized method is tested and visualized in the MATLAB based 2D and 3D environment.
  • Publication
    Design of Reconfigurable Antenna for RFID System
    ( 2021-07-26)
    Renukka Sivakumar
    ;
    Thennarasan Sabapathy
    ;
    Muzammil Jusoh
    ;
    Soh Ping Jack
    ;
    Mohamed Nasrun Osman
    ;
    Salem Al-Bawri S.
    ;
    Jayaprakasam S.
    ;
    Mohd Najib Mohd Yasin
    ;
    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
    Mitigating mutual coupling effects on circular polarization for improved bandwidth in MIMO systems: A novel approach
    ( 2024-03-30)
    Ali A.
    ;
    Mohd Najib Mohd Yasin
    ;
    Ismahayati Adam
    ;
    Ismail A.M.
    ;
    Soh Ping Jack
    ;
    Alghaihab A.
    ;
    Nor N.I.M.
    ;
    Rahman N.A.A.
    An improved mutual coupling compensation in circularly polarized (CP) multi-input multi-output (MIMO) dielectric resonator antenna (DRA) is presented in this paper. Using trimming approach, the mutual coupling (MC) between closely spaced DRA units at 0.3λ has been significantly reduced while axial ratio performance has been maintained. Mutual coupling reduction is obtained by trimming the DRA to ensure low mutual coupling below −20dB. The exclusive features of the proposed MIMO DRA include wide impedance matching bandwidth (BW), triple band circular polarization, and suppressed MC between the radiating elements. The impedance bandwidth matches perfectly with a triple band's 3 dB axial ratio (AR). It is designed with characteristic mode analysis with good agreement of the measurement that has been obtained. Using the probe feed method, the DRA and patch strip are coupled together to allow bandwidth widening of the pro-posed DRA. An impedance bandwidth of 34% at a lower frequency to around 2% at a higher frequency was achieved in all resonance frequencies. Thus, we refer to our newly designed DRA as a proposed method for effectively reducing the mutual coupling between DRAs. Additionally, the 3 dB AR bandwidth matched at 3.3 GHz, 4.6 GHz, and 6.3 GHz with a percentage of 11.66%, 3.04%, and 2.22% obtained at the three different frequencies. Note that the proposed DRA exhibits low mutual coupling (below −20 dB) at the targeted frequencies, which is suitable for better signal reception for MIMO applications. By computing, the metrics envelop correlation coefficient, diversity gain, channel capacity loss, and total active reflection coefficient, the MIMO performance of the proposed antenna is verified. The experiments show a close result between simulated and computed validation of the proposed DRA.