Norfatihah Bahari
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Norfatihah Bahari
Official Name
Norfatihah, Bahari
Alternative Name
Bahari, N.
Bahari, Norfatihah
Bahari, N. I.
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Scopus Author ID
56610151300
Researcher ID
CCZ-6056-2022

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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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Shape Recognition of GPR Images using Hough Transform and PCA plus LDA

2022-01-01 , Hasimah Ali , Norfatihah Bahari , Mohamed Elshaikh Elobaid Said Ahmed , Siti Nurul Aqmariah Mohd Kanafiah , Amran T.S.T. , Jusman Y.

Ground penetrating radar (GPR) is a nondestructive test used for shallow subsurface investigation such as land mine detection, mapping and locating buried utilities. In practical applications, GPR images could be noisy due to system noise, the heterogeneity of the medium, and mutual wave interactions. Hence, it is a complex task to recognize the hyperbolic pattern from GPR B-scan images. Thus, this project proposes combined shape recognition of buried objects using Hough Transform (HT) and PCA plus LDA in GPR images. The use of HT is justified because it has the property of transforming global curve detection into efficient peak detection in the Hough parameter space. Whereas PCA plus LDA tries to maximize between-class scatter while minimizing within-class scatter. In this framework, the preprocessed GPR images were extracted using HT. The extracted HT features were subjected to PCA plus LDA to map them from high into lower dimensional features. Then, the reduced PCA+LDA features were used as input to the k-NN classifier to recognize four geometrical shapes cubic, disc, and spherical of the buried objects. Based on the results obtained, the average recognition rate of reduced HT features using PCA plus LDA was achieved 85.30% thus shows a promising result.

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Compact bidirectional circularly polarized dedicated short range communication antenna for on-board unit vehicle-to-everything applications

2020-05-01 , Rahman N.A.A. , Mohd Aminudin Jamlos , Jamlos M.F. , Soh Ping Jack , Norfatihah Bahari , Hossain T.M.

This article presents a newly circularly polarized (CP) antenna for V2X's dedicated short range communications applications. Its CP characteristic is enabled by a 70 Ω sequential phase feeding network and sequential rotation technique designed on top of the substrate. It has features of ≈90° phase difference in sequence between ports of S21 = 2.4°, S31 = −87°, S41 = −180°, and S51 = −276°, resulting in a 2.19 dB axial ratio centered at 5.9 GHz. The length of the SP feeding network to each ports designed in the different form of meander lines are the key to control the generated phase at the center frequency It also contributes to the smaller final size of 0.59λ × 0.59λ. The proposed antenna operated from 5.850 to 5.925 GHz with a gain between 4 and 6 dBi. The gains are radiated in bidirectional mode due to the presence of the complimentary dipoles located on the opposite side of the substrate. These features indicate the suitability of the proposed antenna in compliance to the ITS-G5 OBU V2X standard.

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A triangular MIMO array antenna with a double negative metamaterial superstrate to enhance bandwidth and gain

2020-08-01 , Ojo R. , Jamlos M.F. , Soh Ping Jack , Mohd Aminudin Jamlos , Norfatihah Bahari , Lee Y.S. , Al-Bawri S.S. , Abdul Karim M.S. , Khairi K.A.

Multiple-input-multiple-output (MIMO) array antenna integrated with the double negative metamaterial superstrate is presented. The triangular metamaterial unit cell is designed by combining two triangular elements positioned in complementary on the same plane at different sizes. Such design with more gaps is used to excite rooms for more capacitance effects to shift the resonance frequency thus enlarging the bandwidth of the MIMO antenna. The unit cell is arranged in 7 × 7 periodic array created a superstrate metamaterial plane where the Cstray exists in parallel between the two consecutive cells. It is found that the existence of Cstray and gaps for each unit cells significantly influenced the bandwidth of the MIMO antenna. The higher value of the capacitance will lead to the negativity of permittivity. The superstrate plane is then located on top of the 4 × 2 MIMO with a gap of 5 mm. The integration resulted in improving the bandwidth to 12.45% (5.65-6.4GHz) compared to only 3.49% bandwidth (5.91-6.12GHz) of the MIMO antenna itself. Moreover, the negative permeability characteristic is created by a strong magnetic field between the complementary unit cells to have 14.05-dBi peak gain. Besides that, the proposed antenna managed to minimize the mutual coupling and improve the mean effective gain, envelope correlation coefficient, and multiplexing efficiency.

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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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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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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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Gain enhancement of microstrip patch antenna using artificial magnetic conductor

2019-03-01 , Norfatihah Bahari , Jamlos M.F. , Muammar Mohamad Isa

The paper presents an artificial magnetic conductor (AMC) structure to enhance the gain of the double microstrip patch antenna. By placing this kind of metamaterial in between the two Rogers RT5880 substrates, the antenna achieved lots of improvement especially in terms of size miniaturization, bandwidth, return loss, gain and efficiency. The antenna is intended to operate at 16 GHz where the prospect fifth generation (5G) spectrum might be located. Integration of AMC structure into the proposed antenna helps to improve nearly 16.3% of gain and almost 23.6% of size reduction.

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A switchless pentagon-shaped reconfigurable antenna for radar applications

2020 , Norfatihah Bahari , Rashidah Che Yob , Liyana Zahid

This paper proposes a switchless pentagon-shaped microstrip patch antenna for radar and radionavigation applications. The antenna is built on Rogers RT5880 substrate with five rectangular radiating elements on top. Five ports have been set up to operate at 13.5 GHz resonant frequency. Besides having reflection coefficient below -10 dB, the antenna also offers high gain when about 8.29 dB is achieved. The proposed antenna also has a bi-directional radiation pattern with 360° of beam steering.

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An IoT-based automated gate system using camera for home security and parcel delivery

2024-02-08 , Mohd Wafi Nasrudin , Jamaluddin A.F. , Ismail I. , Norfatihah Bahari , Vijayasarveswari Veeraperumal , Wan Azani Wan Mustafa , Abdul Syafiq Abdull Sukor , Abdul Rahim A.N.

The Internet of Things (IoT) has made it possible to set up smart home security and parcel delivery. Therefore, this work proposed an automated gate system using camera for home security and parcel delivery with integrated Internet of Things (IoT). An automated gate system will capture and identify the image of face visitors and delivery riders for admin authentication to open the gate and parcel box. This proposed work is controlled and monitored through mobile apps. The primary purpose and inspiration of this work are to help the delivery rider put the parcel into the parcel box provided if there is no person in the house, and the owner can pick up the parcel without being broken or robbed when she/he comes back home. When the delivery rider presses the button near the gate, the admin will receive the notification "Someone coming,". The admin will click the "okay"button and the system will take a picture using the camera in Blynk App. After the admin verifies that is the delivery rider, the admin will open the box and the delivery rider can access the parcel door box and put the goods inside the box. Another advantage of this work, it also allows familiar people to access our home. The same process with the delivery rider where the visitor needs to press the bell and the admin needs to verify before the visitor can access the single gate. The result indicates that this work is able to monitor and control the gate and parcel door box using an IoT application.

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