Khairul Najmy Abdul Rani
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Preferred name
Khairul Najmy Abdul Rani
Official Name
Abdul Rani, Khairul Najmy
Alternative Name
Rani, Khairul Najmy Abdul
Rani, Khairul Najmy Abd
Rani, K. N.A.
Abdul Rani, K. N.
Rani, Khairul N.Abdul
Abdul Rani, Khairul Najmy
Rani, K. N.Abdul
Main Affiliation
Scopus Author ID
57210770305
Researcher ID
GBP-6810-2022

Research Output
Now showing 1 - 10 of 19
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Perpendicular High Isolation MIMO Antenna

2022-01-01 , Mohd Aminudin Jamlos , Sabri N.H.M. , Wan Azani Wan Mustafa , Khairul Najmy Abdul Rani , Syed Zulkarnain Syed Idrus , Husna H.

This research presented a perpendicular high isolation MIMO antenna for LTE advance application. A high gain perpendicular MIMO antenna is concentrated on designing used in LTE advance application. The issues of low isolation of conventional antenna can be solved by structuring a MIMO antenna in order to increase the isolation in LTE advance application. Generally, the array antenna design causes a bigger antenna size and has a mutual coupling which lead to spectral efficiency damage and reduce the MIMO antenna framework performance. The substrate material like FR-4 is choosing as a dielectric substrate due to its good performances for many applications beside it has a low cost and more usable. The advantage of copper such as has a great relative material, cheaper and easy to construct is choose in this project as a conductive material. ADS software has been utilized for the structure stage to design the antenna. Then, the results are evaluated in terms of return loss (S11 and S22), mutual coupling (S12 and S21), match impedance, directivity, radiation pattern, gain and radiated power. Vector Network Analyzer (VNA) is used to measure the fabricated antenna. The factor of cable loses and the soldering technique will make the measurement result was slightly change from the simulating result. However, the antenna design satisfied the proficiency necessity of the antenna which the frequency is drop at 2.5 GHz with the return loss is below than −10 dB.

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Publication

Linear antenna array synthesis using the enhanced and hybrid cuckoo search metaheuristic algorithms

2014 , Khairul Najmy Abdul Rani

The antenna geometry synthesis plays an important role to determine the physical layout of the antenna array, which produces the radiation pattern closest to the actual desired pattern. The synthesis can be realized by defining the location of antenna array elements, and by choosing suitable excitation of amplitude, and excitation phase applied on the antenna array elements. Many synthesis techniques are done through suppressing the side lobe level (SLL) and/or mitigating prescribed nulls while simultaneously maintaining or improving the major lobe radiation intensity. Studies show that some conventional analytical, numerical, and modern evolutionary algorithm (EA) or evolutionary computation (EC) techniques have certain limitations in antenna array geometry synthesis. This includes beamwidth expanding and directivity saturation in amplitude tapering, exhaustive checking impairment in analytical method, disparity predicament between local and global search accelerators in particle swarm optimization (PSO), and drawbacks of crossover and mutation operators in genetic algorithm (GA). This thesis presents the sequential development of enhanced and hybrid versions of cuckoo search (CS) metaheuristic algorithm as an alternative of EA/EC technique for symmetric linear antenna array synthesis. Firstly, the proposal of the modified CS (MCS) algorithm through the integration with the Roulette wheel selection operator, dynamic inertia weight, and dynamic discovery rate controlling the best solutions exploration for a single objective (SO) optimization. Secondly, there is the hybridization of MCS with PSO (MCSPSO), and MCS with GA (MCSGA) in both SO and weighted−sum multiobjective (MO) approaches. Thirdly, the proposed amalgamation of MCS with strength Pareto evolutionary algorithm (MCSSPEA), hill climbing (HC) stochastic method within MCSSPEA algorithm (MCSHCSPEA), and PSO within MCSSPEA algorithm (MCSPSOSPEA) equipped with distance expansion formulae to reduce local trap problem. These newly techniques are specifically for Pareto MO optimization to find non−dominated solutions including element location, excitation amplitude, and excitation phase. All the tested algorithms development, source code writing, and results execution are performed using MATLAB scientific software. The optimal solutions are then compared against corresponding counterparts. Based on simulation results, the proposed MCSPSO outperforms other SO and weighted−sum MO algorithms whereas the proposed MCSPSOSPEA algorithm surpasses other tested Pareto MO algorithms in SLL suppression and/or nulls mitigation whilst achieving a high linear antenna directivity, and small half−power beamwidth (HPBW), respectively.

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A hybrid modified method of the sine cosine algorithm using latin hypercube sampling with the cuckoo search algorithm for optimization problems

2020-11-01 , Siti Julia Rosli , Hasliza A Rahim @ Samsuddin , Khairul Najmy Abdul Rani , Yahaya N.Z. , R Badlishah Ahmad , Ruzelita Ngadiran , Abdulmalek M. , Muzammil Jusoh , Mohd Najib Mohd Yasin , Thennarasan Sabapathy , Allan Melvin Andrew

The metaheuristic algorithm is a popular research area for solving various optimization problems. In this study, we proposed two approaches based on the Sine Cosine Algorithm (SCA), namely, modification and hybridization. First, we attempted to solve the constraints of the original SCA by developing a modified SCA (MSCA) version with an improved identification capability of a random population using the Latin Hypercube Sampling (LHS) technique. MSCA serves to guide SCA in obtaining a better local optimum in the exploitation phase with fast convergence based on an optimum value of the solution. Second, hybridization of the MSCA (HMSCA) and the Cuckoo Search Algorithm (CSA) led to the development of the Hybrid Modified Sine Cosine Algorithm Cuckoo Search Algorithm (HMSCACSA) optimizer, which could search better optimal host nest locations in the global domain. Moreover, the HMSCACSA optimizer was validated over six classical test functions, the IEEE CEC 2017, and the IEEE CEC 2014 benchmark functions. The effectiveness of HMSCACSA was also compared with other hybrid metaheuristics such as the Particle Swarm Optimization–Grey Wolf Optimization (PSOGWO), Particle Swarm Optimization–Artificial Bee Colony (PSOABC), and Particle Swarm Optimization–Gravitational Search Algorithm (PSOGSA). In summary, the proposed HMSCACSA converged 63.89% faster and achieved a shorter Central Processing Unit (CPU) duration by a maximum of up to 43.6% compared to the other hybrid counterparts.

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Mobile Green E-Waste Management Systems using IoT for Smart Campus

2021-07-26 , Khairul Najmy Abdul Rani , Hasliza A Rahim @ Samsuddin , Ong B.T. , Muzammil Jusoh , Mohd Najib Mohd Yasin , Thennarasan Sabapathy , Wan Azani Wan Mustafa , Mohd Aminudin Jamlos , R Badlishah Ahmad , Hammood D.A.

This paper presents the design and development of mobile "green"electronic waste (e-waste) management systems using Internet of Things (IoT) for smart campus. The system uses Raspberry Pi 3 Model B v1.2 microcontroller for monitoring e-waste object detection, e-waste count, and bin percentage level, respectively. TensorFlow Lite application programming interface (API) is used to run Single Shot Multibox Detector (SSD)Lite-MobileNet-v2 model trained on Microsoft Common Objects in Context (MSCOCO) dataset for e-waste object detection in image. All the monitoring data are stored and retrieved in ThingSpeak cloud platform using Hypertext Transfer Protocol (HTTP) and Message Queuing Telemetry Transport (MQTT) protocol over the Internet and displayed via interactive Android-based mobile user interface (UI). Furthermore, automatic e-mail notification will be sent to waste collector for bin collection whenever e-waste bin percentage level is greater than predetermined threshold value of 80% full.

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Hybridization of strength pareto multiobjective optimization with modified Cuckoo search algorithm for rectangular array

2017-04-20 , Khairul Najmy Abdul Rani , Mohamedfareq Abdulmalek , Hasliza A Rahim @ Samsuddin , Neoh Siew Chin , Alawiyah Abd Wahab

This research proposes the various versions of modified cuckoo search (MCS) metaheuristic algorithm deploying the strength Pareto evolutionary algorithm (SPEA) multiobjective (MO) optimization technique in rectangular array geometry synthesis. Precisely, the MCS algorithm is proposed by incorporating the Roulette wheel selection operator to choose the initial host nests (individuals) that give better results, adaptive inertia weight to control the positions exploration of the potential best host nests (solutions), and dynamic discovery rate to manage the fraction probability of finding the best host nests in 3-dimensional search space. In addition, the MCS algorithm is hybridized with the particle swarm optimization (PSO) and hill climbing (HC) stochastic techniques along with the standard strength Pareto evolutionary algorithm (SPEA) forming the MCSPSOSPEA and MCSHCSPEA, respectively. All the proposed MCS-based algorithms are examined to perform MO optimization on Zitzler-Deb-Thiele's (ZDT's) test functions. Pareto optimum trade-offs are done to generate a set of three non-dominated solutions, which are locations, excitation amplitudes, and excitation phases of array elements, respectively. Overall, simulations demonstrates that the proposed MCSPSOSPEA outperforms other compatible competitors, in gaining a high antenna directivity, small half-power beamwidth (HPBW), low average side lobe level (SLL) suppression, and/or significant predefined nulls mitigation, simultaneously.

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Split Ring Resonator Array Metamaterial of Zero Index Unit Cell Configuration

2022-01-01 , Mohd Aminudin Jamlos , Othman N.A. , Wan Azani Wan Mustafa , Hasliza A Rahim @ Samsuddin , Al-Kharasan I.H. , Khairul Najmy Abdul Rani

A split-ring resonator (SRR) array metamaterial of zero-index unit cell configuration has been proposed. The SRR is made up of four loops; r1, r2, r3, and r4, which are inductance related, and the gaps (slots) are introduced to the ring to create the capacitance effect. The split ring is designed and simulated using sophisticated simulation software to have accurate simulation results. The SRR is placed between two waveguide terminals on the z-axis, at the top and bottom of the z-axis, respectively. SRR unit cell is configured into two array structures with a size of 110 x 65 mm2 which are the 7 x 4-unit cell and the 10 x 5-unit cell. A parametric study has been carried out for the split ring resonator to find the optimized design to have zero index as well as positive permittivity and permeability at the desired frequency of 2.7 GHz. Both array configurations recorded zero index (phase) at the desired frequency of 2.70 GHz. The positive on the point of close to zero results of the real part of permittivity and permeability lies at frequency 2.70 GHz as well.

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Publication

Hybridization of strength pareto multiobjective optimization with modified cuckoo search algorithm for rectangular array

2017 , Khairul Najmy Abdul Rani , Mohamedfareq Abdulmalek , Hasliza A Rahim @ Samsuddin , Neoh Siew Chin , Alawiyah Abd Wahab

This research proposes the various versions of modified cuckoo search (MCS) metaheuristic algorithm deploying the strength Pareto evolutionary algorithm (SPEA) multiobjective (MO) optimization technique in rectangular array geometry synthesis. Precisely, the MCS algorithm is proposed by incorporating the Roulette wheel selection operator to choose the initial host nests (individuals) that give better results, adaptive inertia weight to control the positions exploration of the potential best host nests (solutions), and dynamic discovery rate to manage the fraction probability of finding the best host nests in 3-dimensional search space. In addition, the MCS algorithm is hybridized with the particle swarm optimization (PSO) and hill climbing (HC) stochastic techniques along with the standard strength Pareto evolutionary algorithm (SPEA) forming the MCSPSOSPEA and MCSHCSPEA, respectively. All the proposed MCS-based algorithms are examined to perform MO optimization on Zitzler–Deb–Thiele’s (ZDT’s) test functions. Pareto optimum trade-offs are done to generate a set of three non-dominated solutions, which are locations, excitation amplitudes, and excitation phases of array elements, respectively. Overall, simulations demonstrates that the proposed MCSPSOSPEA outperforms other compatible competitors, in gaining a high antenna directivity, small half-power beamwidth (HPBW), low average side lobe level (SLL) suppression, and/or significant predefined nulls mitigation, simultaneously.

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Artificial Magnetic Conductor to Enhance Microstrip Patch Textile Antenna Performance for WiMAX Application

2020-12-18 , Liyana Zahid , Hanif Suhairi Abu Bakar , Khairul Najmy Abdul Rani , Thennarasan Sabapathy , Mohd Aminudin Jamlos , Mohamad Rizal Abdul Rejab , Khairil Syahmi Musa , Hamzah D. , Rashidah Che Yob , Norfatihah Bahari

A rectangular microstrip patch textile antenna with Artificial Magnetic Conductor (AMC) operated at the center frequency of 5.80 gigahertz (GHz) for Worldwide Interoperability for Microwave Access (WiMAX) application was designed and simulated using the CST Microwave Studio 2016 and fabricated in this study. The use of AMC could solve the inflexibility of FR4 substrate that limits human body movement and reduce the radiation scattered on the human body whilst increasing the antenna gain and directivity. The antenna consists of 5 5 square shape gap of AMC unit cells ground layer using ShieldIt Super, five substrate layers using cotton (viscose) fabric as well as patch layer and another ground layer using the same ShieldIt Super. AMC is a metamaterial that imitates the conduct of zero reflection phase of Perfect Magnetic Conductor (PMC) on the resonant frequency not evidently existed in nature. Overall, the antenna with AMC has the significant return loss, S11 below than -30 decibel (dB), gain improved to more than 8 dB, and directivity elevated to more than 9 dBi at resonant frequency near to 5.80 GHz, respectively.

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Design of A 20-Bit Chipless RFID Tag Utilizing Multiple Resonators in UWB Frequency Range

2023-01-01 , Radhakrishna K. , Khairul Najmy Abdul Rani , Wahab A.A. , Siti Julia Rosli , Hasliza A Rahim @ Samsuddin , Seng L.Y. , Omar M.H. , Khairul Affendi Rosli

Radio frequency identification (RFID) is a growing technology for monitoring and recognizing objects, persons, or animals via wireless communications. Precisely, RFID can operate longer range and has an ability to be automated without human control. Chipless RFID tag basically is a RFID tag that does not require a microchip in the transponder. The major impediments in designing chipless RFID tag are data encoding and transmission. The passive chipless RFID tag can be fabricated on any substrate material without external operating circuit, which is different compared to a conventional chipped RFID tag. In this paper, 20 resonators are used to design a 20-bit chipless RFID tag, which operates at the ultra-wideband (UWB) frequency range between 3.00 and 10.00 GHz. It is found that the additional resonators can encode data and increase the chipless RFID tag's encoding capacity significantly. In sum, multiple resonators enable the chipless RFID tag to encode data at different operating frequencies.

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5.8 GHz Circularly Polarized Rectangular Microstrip Antenna Arrays simulation for Point-to-Point Application

2022-11-01 , Mohd Aminudin Jamlos , Sabri N.H.M. , Jamlos M.F. , Wan Azani Wan Mustafa , Syed Zulkarnain Syed Idrus , Mohamad Nur Khairul Hafizi Rohani , Khairul Najmy Abdul Rani , Mohd Al-Hafiz Mohd Nawi

In this paper, the design and simulation of rectangular microstrip antenna arrays for improving antenna gain is performed for point-to-point application. The circular polarization is proposed to restrict the limitation of linear polarization which is less reliable in base station antenna. The circular polarization antenna is made to allow the receiver constantly to receive the power at any wave angle and make the transmission between two antennas are more constant. The proposed design is composed of four elements microstrip antenna with an array configuration operating at 5.8 GHz. Each element is constructed from four truncated arrays radiating elements and an inclined slot on each patch which capable to achieve circular polarized capability. The design of the 2x1 and 2x2 of rectangular microstrip array antenna was implemented from the design of single rectangular patch antenna as the basic building element. The designed 2x1 and 2x2 array were fed by microstrip transmission line which applied a technique of quarter wave impedance matching. The antenna design was etched on Rogers RT 5880 substrate with 2.1 and 1.53 mm of dielectric constant and thickness respectively. All the designed structure were simulated in CST software. The main results of the designed antennas were compared in terms of gain, axial ratio and return loss. Based on the return loss simulation results, the designed antennas resonated exactly at the desired resonant frequency of 5.8 GHz which indicates good antenna designs. Compared to the single patch antenna having an antenna gain of 8.26 dB, the 2x1 and 2x2 arrays achieved a gain of 10.24 dB and 13.29 dB respectively. The results show that the designed rectangular microstrip antenna arrays have an improved gain performance over the single patch antenna.

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