Nazuhusna Khalid
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Preferred name
Nazuhusna Khalid
Official Name
Nazuhusna, Khalid
Alternative Name
Nazuhusna, Khalid
Khalid, N.
Main Affiliation
Scopus Author ID
35208616600
Researcher ID
CZJ-6151-2022

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Remazol orange dye sensitized solar cell

2017-01-03 , Siti Salwa Mat Isa , Muhammad Mahyiddin Ramli , Nor Azura Malini Ahmad Hambali , Muda M.R. , Shahrir Rizal Kasjoo , Muammar Mohamad Isa , Nurul Izza Mohd Nor , Norhawati Ahmad , Nazuhusna Khalid , Nur M. Selamat , Nur Asyikin Mohd Anhar

Water based Remazol Orange was utilized as the dye sensitizer for dye sensitized solar cell. The annealing temperature of TiO2 working electrode was set at 450 °C. The performance of the device was investigated between dye concentrations of 0.25 mM and 2.5 mM at three different immersion times (3, 12 and 24 hours). The adsorption peak of the dye sensitizer was evaluated using UV-Vis-Nir and the device performance was tested using solar cell simulator. The results show that the performance was increased at higher dye concentration and longer immersion time. The best device performance was obtained at 0.2% for dye concentration of 2.5 mM immersed at 24 hours.

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Comprehensive study on gate recess step for the fabrication of high-speed InGaAs/InAlAs/InP pHEMT

2017-01-03 , Muammar Mohamad Isa , Norhawati Ahmad , Siti Salwa Mat Isa , Muhammad Mahyiddin Ramli , Nazuhusna Khalid , Nurul Izza Mohd Nor , Shahrir Rizal Kasjoo , Missous M.

We report a comprehensive etching study on the gate recess step for the fabrication of the novel high speed pHEMT devices. The experiments focused on the elimination of 'hump' structure as a result of an incomplete etching process at the InGaAs cap layer. In this work, two types of test samples were used, namely bulk InGaAs and epitaxial structure together with an etch stop layer. The result showed that the etch rate of bulk InGaAs is about 360 A/min and the percentage of dome height is consistent at approximately 25%. Meanwhile, the study on pHEMT epitaxial layer showed that the etching time of 3 minutes is sufficient in order to completely remove the cap layer. Gate leakage current of magnitude more than 10 times lower is observed on the devices that engaging Succinic Acid as the gate recess etching agent. The optimized processing steps will tailor for highly reproducible pHEMT fabrication process for high speed applications.

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Analysis on Square and Circular Inductor for a High Q-Factor Inductor

2021-12-01 , Nur Anira Asyikin Hashim , Nazuhusna Khalid , Nurul Izza Mohd Nor , Shahrir Rizal Kasjoo , Zaliman Sauli

This paper presents the high-quality (Q) factor inductors using Silicon-on-sapphire (SOS) for the 10GHz to 20GHz frequency band. Inductors are designed on SOS because of their advantages, including high resistivity and low parasitic capacitance. This paper compares square and circular inductor topologies for high-quality (Q) factor inductors using HFSS software for the high-frequency band. Both inductors have been designed with the same width and thickness to make them comparable with each other. The comparison shows that a circular inductor achieves the highest Q-factor. Furthermore, the circular and square inductor's Q-factor, inductance, and resistance are analyzed. As a result, the circular inductor has the maximum Q-factor of 89.34 at 10.6GHz for 0.29nH, while the square inductor has obtained a maximum Q-factor of 80.72 at 10GHz for 0.40nH inductance.

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Optimization of Symmetric Inductor Parameter for a High Q-Factor Inductor for Wireless Application

2021-08-02 , Nur Anira Asyikin Hashim , Nazuhusna Khalid , Nurul Izza Mohd Nor , Shahrir Rizal Kasjoo , Zaliman Sauli

A high Q-factor (Quality Factor) inductor is essential in Radio Frequency (RF) circuits to achieve demanding specifications for low power consumption and low cost. One of the primary disadvantages of Si-based IC advancements for RF circuit configuration is the Low Q-factor inductor because of the thin metallization and Si substrate loss. This paper presents the comparative analysis of various inductor topologies for high-quality (Q) factor inductors using HFSS software for the high-frequency band in the range between 10GHz and 20GHz. Three topologies of inductors are designed, which are square, circular, and symmetric. Comparison is made amongst the three to determine the highest Q-factor. Inductors are designed on Silicon-On-Sapphire (SOS) because of their advantages having high resistivity and low parasitic capacitance. The analysis of various topologies inductors on the Q-factor, inductance, and resistance are inspected. Results show that the symmetric inductor has the highest Q-factor of 101.002 at 44.2 GHz for 0.198nH and a Q-factor of 60.038 at 12GHz inductance 0.178nH with the same parameter. Further optimization of the parameters such as width, the thickness of metal, and outer diameter for the symmetric inductor shows that the highest Q-factor of 50.22 at 12GHz has been achieved. This paper concludes that the inductor's symmetric topology designed on the SOS substrate has a high Q-factor in the range of 10GHz to 20GHz compared to the square and circular inductor.

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Development of branchline coupler using parallel coupled transmission lines

2017-01-03 , Rahim N.H.A. , Rasid R. , Siti Zuraidah Ibrahim , Nazuhusna Khalid , Mohammad Shahrazel Razalli , Siang T.G.

This paper investigates the development of branchline coupler using parallel coupled transmission lines on planar microstrip using CST Studio Suite 2010 design tool. This project operates within 4 GHz to 8 GHz frequency band. Two designs are proposed in this project which are basic branch line coupler and branch line coupler with parallel line feeding technique. The main purpose of this study is to improve bandwidth while compare the performance of both designed coupler. The designs are then investigated using CST Microwave Studio simulation tool. The designs are fabricated on microstrip printed circuit board and measured using vector network analyzer. The simulated and experimental results of both developed couplers are compared and analyzed. The overall simulated percentage bandwidth of the proposed coupler is covered from 4 to 8 GHz with percentage bandwidth of 32.32%.

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Development of six-port baseband processing system for short range radar based sensor

2017-01-03 , Nurul Ainun Zulkifli , Nazuhusna Khalid , Siti Zuraidah Ibrahim , Tan G.

This paper presents the development of the six-port baseband processing system for short range radar based sensor. Short range radar involved in many applications such as the used in the automotive system. The analog baseband circuit commercially exists nowadays, but it a little bit bulky and expensive. In this paper, the design of a RF power detector using microstrip technique is presented. The design of diode detector circuit is simulated using Keysight ADS software tool. The design of the diode detector includes the matching network, RF choke and the low pass matching. When the design of diode detector completed, the development of baseband processing system is accomplished using microcontroller board. The algorithm of obtaining Direction of Arrival (DOA) phase wave is executed using microcontroller board. The details of the theory, simulation and results are presented in this paper.

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Characteristics of film bulk acoustic wave resonator using different electrode materials

2021-07-21 , Nurul Izza Mohd Nor , Jing Y.W. , Nazuhusna Khalid

Film bulk acoustic wave resonator (FBAR) is a device that consists of a thin-film piezoelectric, which is sandwiched between the top and bottom electrodes. FBAR has been widely used in radio frequency (RF) front-end circuits such as RF filters due to its advantages of high quality (Q) factor. The performance of FBAR is highly related to the piezoelectric material. The piezoelectric material such as aluminum nitride (AlN) and zinc oxide (ZnO) are commonly used in FBAR. Other than piezoelectric material, another important element in designing an FBAR is the electrode materials. Different electrode materials affect the performance of FBAR in terms of Q factor and electromechanical coupling coefficient (k2eff) due to their material properties. Therefore, in this work, FBARs operating at frequencies of 5 GHz to 10 GHz by using AlN as the piezoelectric material with different electrode materials, which are molybdenum (Mo) and aluminum (Al) were designed. The performance of the designed FBARs were compared in terms of Q factor and k2eff. Based on the results, the Q factor of FBAR with Mo as electrodes achieved the highest value of 16300 at 5 GHz, while the Q factor of FBAR with Al as electrodes achieved the highest value of 13726 at 5 GHz. The k2eff of FBAR with Al as electrodes achieved the highest value of 6.71% at 7 GHz, while FBAR with Mo as electrodes achieved the highest coupling coefficient of 5.78% at 6 GHz.

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Directional and wideband antenna for ground penetrating radar (GPR) applications

2017-01-03 , Nazuhusna Khalid , Siti Zuraidah Ibrahim , Mohd Nazri A. Karim

This paper presents a directional and wideband antenna for ground penetrating radar (GPR) applications. The antenna is designed by introducing slots on bowtie patch. The design is implemented on FR4 board with dielectric constant of 4.7 and thickness of 0.8 mm. As a result of having thinner substrate, the design is compact and light weight. The bowtie antenna performance is investigated across 0.5 GHz to 3 GHz. The parametric study of the length and location of slot are also demonstrated in this paper to obtaining the best return loss across widest operational bandwidth. The both simulated and fabricated antenna bandwidth are more than 50% (fractional bandwidth). The additional reflector is included at the back of bowtie antenna in the simulation for obtaining directional radiation pattern and high gain. The comparison between simulated and measured reflection coefficient is also presented.

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The Design and Analysis of High Q Factor Film Bulk Acoustic Wave Resonator for Filter in Super High Frequency

2021-12-01 , Nurul Izza Mohd Nor , Nazuhusna Khalid , Nur Anira Asyikin Hashim , Shahrir Rizal Kasjoo , Zaliman Sauli , Lam Hok Lang , Chow Shi Qi

Filtering process is one of the highlighted issues when the operating frequency is up to medium or high GHz range in wireless transceiver system. The development of high performance, small size, filter on chip operating in GHz frequency range is the requirement of present and future wireless transceiver systems. The conventional frequency bands, below 6 GHz are already congested, thus, to satisfy this demand, the research into transceiver systems working at frequencies higher than 6 GHz has been growing. Therefore, this work proposed the design and optimization of film bulk acoustic wave resonator (FBAR) operating in frequency 7 GHz to 10 GHz with high quality (Q) factor. The effect of using different geometrical parameters to achieve high Q factor FBAR in these frequency bands is analysed. The designed FBAR achieved Q factor of 1767 at 7 GHz and 1237 at 10 GHz by using aluminium nitride as the piezoelectric thin film and molybdenum as the electrode.

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A 12 GHz LC-VCO Implemented with S’ shape Inductor using silicon-on sapphire substrate

2022-12 , Nazuhusna Khalid , Aimi Noorliyana Hashim , Nurul Izza Mohd Nor , Shahrir Rizal Kasjoo , Zaliman Sauli , Mohd Norhafiz Hashim , M.S Mispan

A voltage-controlled oscillator (VCO) is an electronic oscillator whose oscillation frequency is controlled by a voltage input. In a VCO, low-phase noise while consuming less power is preferred. The tuning gain and noise in the control signal produce phase noise; more noise or tuning gain implies more phase noise. Sources of flicker noise (1/f noise) in the circuit, the output power level, and the loaded Q factor of the resonator are all crucial factors that influence phase noise. As a result, creating a resonator with a high Q-factor is essential for improving VCO performance. As a result, this paper describes a 12 GHz LC Voltage- Controlled Oscillator (VCO) employed with a ‘S’ shape inductor to improve phase noise and power performance. The phase noise for the VCO was reduced using a noise filtering technique. To reduce substrate loss and improve the Q factor, the inductor was designed on a high-resistivity Silicon-on Sapphire (SOS) substrate. At 12 GHz, the optimised S’ shape inductor has the highest Q-factor of 50.217. At 10 MHz and 100 MHz, the phase noise of the 12 GHz LC-VCO was -131.33 dBc/Hz and -156.71 dBc/Hz, respectively. With a 3.3 V power supply, the VCO core consumes 26.96 mW of power. Based on the findings, it is concluded that using an ‘S’ shape inductor in the VCO circuit will enable the development of low-cost, high-performance, very low-power system-on-chip wireless transceivers with longer battery life.

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