Nur Hidayah Ramli
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Preferred name
Nur Hidayah Ramli
Official Name
Nur Hidayah, Ramli
Alternative Name
Ramli, Nur Hidayah Binti
Ramli, Nur Hidayah
Ramli, Nur H.
Ramli, Nurhidayah
Ramli, N. H.
Main Affiliation
Scopus Author ID
57210707435

Research Output

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Electromagnetic properties performance of MWCNTs/Polyester composites in X-band

2018 , Y. S. Lee , F. H. Wee , K. Y. You , C. Y. Lee , Y. Y. Lee , L. Zahid , Nur Hidayah Ramli , M. S. Shakhirul , Nurulbariah Idris , E. M. Cheng

In this paper presents nano-composites based on polyester (PE) matrix with multi-walled carbon nanotubes (MWCNTs) as fillers have been developed for microwave absorbing materials. The MWCNTs/PE composite samples were fabricated with different weight ratio of MWCNTs (3 wt%, 5 wt%, and 10 wt%). The electromagnetic properties of different MWCNTs/PE composite have been determined by using rectangular waveguide technique and Agilent material measurement software. Moreover, the reflection loss (microwave absorption) of MWCNTs/PE composite have been calculated based on the basis of transmission line theory. The performance of electromagnetic properties and microwave absorption of MWCNTs/PE composite were analyzed in X-band frequency. The dielectric loss properties of the composite are increse with increasing in MWCNTs weight ratio. The microwave absorption results show that such 3 wt% MWCNTs/PE composites sample with 4 mm thickness has achieved less than -10 dB values (< 90 % microwave absorption) of reflection loss.

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Dual-Band MIMO Decagonal C-Shaped CSRR Metamaterial Textile Antenna for WLAN and 5G Applications

2023-01-01 , Mashagba H.A. , Hasliza A Rahim @ Samsuddin , Mohd Najib Mohd Yasin , Narongkul S. , Liyana Zahid , Nur Hidayah Ramli

This study proposed an enhanced two-port dual-band textile Multiple-Input Multiple-Output (MIMO) antenna integrated with a metamaterial unit cell of symmetric decagonal C-shaped Complementary Split-Ring Resonator (CSRR) structure in terms of gain. The proposed MIMO antenna achieves an impedance bandwidth of 6.3% and a maximum up to 18.2% for lower and upper bands, respectively, at port 1. Mutual Coupling (MC) of less than -20 dB for both ports is obtained. The proposed antenna offers high realized gain of 5.6 dBi and 8 dBi at 2.45 GHz and 3.5 GHz, respectively, compared to existing dual-band MIMO textile antenna. Good diversity characteristics in respect of Envelope Correlation Coefficient (ECC) less than 0.001, and Diversity Gain (DG) of about 10 dB are achieved.

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Cylindrical Dielectric Resonator as Dielectric Matching on Microwave Amplifier for the Unconditionally Stable and Conditionally Stable Transistor at 5 GHz Frequency

2022-12-01 , Rashidah Che Yob , Mahyuddin N.M. , Ain M.F. , Mohd Aminudin Jamlos , Nur Hidayah Ramli , Norfatihah Bahari , Mohd Wafi Nasrudin , Liyana Zahid

Stability and matching techniques on microwave amplifier have been an important consideration to maintain their required performances, but typically its frequency dependent. Thus, a frequency variable mechanism is required. The dielectric matching employing the stability and matching techniques on microwave amplifier with cylindrical dielectric resonator has been investigated and realized. The cylindrical dielectric resonator (CDR) with parallel microstrip lines is proposed at 5 GHz frequency for unconditionally stable and conditionally stable transistor as dielectric matching. Hence, the proposed dielectric resonator with +2 mm spacing and 155Ëš of curved configuration indicated the best performances for preliminary study. The result improves the performance of the parallel inhomogeneous CDR by 9.77%. Subsequently, the homogeneous CDR is also successfully working as the variable frequency mechanism for unconditionally stable and conditionally stable transistor at 5 GHz frequency in maintaining their stability performances.

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Comparison of RFID Tag structure for wearable applications system

2025-04 , Nur Hidayah Ramli , Rashidah Che Yob , Liyana Zahid , Norfatihah Bahari

This paper proposed a comparison of Radio- Frequency Identification (RFID) tags for wearable applications. Three types of proposed RFID tag structures are designed which are square, hexagonal, and octagonal shapes to operate at frequencies 1.0GHz to 12GHz. The RFID tag structure consists of several meander line radiators. The structure of the meandered line radiator is attached to the cotton and jeans fabric. A monostatic radar system which consists of a Vector Network Analyzer and a horn antenna is configured to test the RFID tag in real life. The performances of RFID tags are evaluated in terms of the reflection coefficient (S11) and their operating frequency. The results will be guidelines while designing RFID tag structures for wearable application systems in the future.

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Antenna Performance Enhancement using AMC Structure for 5G Frequency Range

2023-02-01 , Norfatihah Bahari , Rokhizan M.Z.N. , Rashidah Che Yob , Mohd Wafi Nasrudin , Nur Hidayah Ramli , Mohd Aminudin Jamlos , Lago H.

This paper presents a microstrip patch antenna operated at the fifth generation (5G) frequency range, which is at 3.5 GHz. To enhance the performance of the proposed antenna, an Artificial Magnetic Conductor (AMC) structure is implemented into the design. The 1x3 AMC is sandwiched between two FR-4 substrates and the performance of the proposed antenna is compared with the antenna without AMC structure. The simulated results prove that the proposed antenna offers better reflection coefficient with-50.45 dB compared to only-15.55 dB for the conventional antenna. Wider bandwidth is also achieved with 427 MHz of frequency bandwidth as opposed to only 135 MHz for the antenna without AMC. Besides that, the integration of AMC enhances the gain of the antenna when 3.7 dBi is achieved in contrast to only 3.21 dBi for the conventional antenna. Moreover, the efficiency of the antenna with AMC is also improved up to 68.54%. Furthermore, the ability to shrink 52.23% of the size of the antenna without AMC making it very favorable to be applied in 5G bands.

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Advanced control strategies for managing circulating currents in islanded microgrid inverters

2025-06 , Mohd Hafizuddin Mat , Nur Hidayah Ramli , Nurul Husna Abd Wahab , Norezmi Md Jamal

In islanded microgrids, circulating currents among parallel inverters pose significant challenges to system stability and efficient power distribution. Traditional droop control methods often struggle to manage these currents effectively, leading to inefficiencies and potential system damage. This study introduces an advanced fuzzy-robust droop control strategy that integrates fuzzy logic with robust droop control to address these challenges. By incorporating fuzzy logic, the proposed strategy enhances the adaptability of droop control to varying system conditions, improving the management of circulating currents and ensuring more accurate power sharing among inverters. Comprehensive mathematical modeling and extensive simulation analyses validate the performance of this control strategy. The results show that the fuzzy-robust droop control method significantly outperforms conventional approaches, achieving up to a 70% reduction in circulating currents. This improvement leads to a substantial reduction in power losses and enhances the dynamic response under varying load conditions. Additionally, the strategy improves voltage and frequency regulation, contributing to the overall stability and reliability of the microgrid. The findings provide a robust solution to the longstanding issue of circulating currents, optimizing microgrid operations, and paving the way for more efficient and resilient distributed energy systems. The advanced control strategy presented in this study not only addresses critical challenges but also demonstrates the potential for innovative methodologies to meet the growing demands of future energy infrastructures, where reliability and efficiency are essential.

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IoT based earthquake detection system

2025-09 , Norfatihah Bahari , Nor Irfan Multazam Nor Azmi , Herwansyah Lago , Mohd Wafi Nasrudin , Rashidah Che Yob , Nur Hidayah Ramli

This paper proposes an IoT based Earthquake Detection System for the early warning and quick detection of the earthquake. Earthquakes are one of the rare natural disasters in Malaysia but when the earthquake happened, it could damage infrastructure and cause deaths. This system is aimed to monitor the earthquake levels and warn people about earthquake dangers. To detect the vibration on the ground surface, an accelerometer has been connected to the microcontroller Arduino Uno R3. Then NRF24L01 transceiver module has been used to connect between the transmitter and receiver part. In order to receive the notifications about the earthquake, the ESP8266 Wi-Fi module is linked to the Blynk App. This proposed system is very user-friendly and economical, making it favourable to be used in the earthquake zones.

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Review on Patch Antennas for Unmanned Aerial Vehicle Application

2023-11-01 , Nur Hidayah Ramli , Seng L.Y. , Liyana Zahid , Hazry Desa

The wide-ranging Unmanned Aerial Vehicle (UAV) applications make them one of the Internet of Things promising technologies. The vast potential of monitoring and surveillance for public safety threats using drones is a current issue for researchers. Antennas play an important part in UAV to create reliable communication links. There are different types of antennas that can be used for UAV application depending on antennas size, efficiency, gain, angle of radiation pattern, polarization, etc. This paper mainly focuses on patch antennas for UAV applications. In general, there are two types of patch antenna described which are single patch antenna and array antenna. The review of patch antennas can be a useful guideline to choose or design antenna for UAV applications in the future.

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Left-handed metamaterial wearable antenna at 5G frequency range for wireless body area network

2023 , Nur Hidayah Ramli , Muhammad Afif Farhan Lokman , Norfatihah Bahari , Liyana Zahid , Rashidah Che Yob , Mohd Hafizuddin Mat , Mohd Aminudin Jamlos , Laith H. Alzubaidi , Abbas Hameed Abdul Hussein

Wearable antennas are typically required to be small in weight, provide high bandwidth, high gain and efficiency, low price, and be installation-free for many modern applications. Due to the non-static human movement, an antenna with wide-angle scanning is necessary. This project is carried out by designing a small metamaterials wearable antenna at a 5G frequency range. The combination of left-handed metamaterial (LHM) and the wearable antenna is designed to operate for such a system. Results prove that the small wearable metamaterial antenna offers good performances where the gain is 5.8 dBi with an efficiency of 91.86% and provides an omnidirectional radiation pattern compared to the wearable antenna without LHM structure. The communication links of the antenna between the base station and the human body are investigated. The antenna can receive the signals for long distances may be up to 2 meters with wide angles. All the results will be a guideline while designing the systems in the future.

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