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Nazuhusna Khalid
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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1 - 10 of 18
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PublicationRemazol orange dye sensitized solar cell( 2017-01-03)
;Siti Salwa Mat Isa ;Muda M.R. ;Nur M. SelamatNur Asyikin Mohd AnharWater 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. -
PublicationDevelopment of branchline coupler using parallel coupled transmission lines( 2017-01-03)
;Rahim N.H.A. ;Rasid R.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%. -
PublicationAnalysis on square and circular inductor for a high Q-factor inductor( 2021-12)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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PublicationTarget direction finding using port technique for short range radar based sensor( 2017-01-03)
;Ghazali S.Tan G.This paper presents a target direction finding using six-port technique for short range radar based sensor. Direction finding of the target is determined by performing phase measurement of the incident wave at the receiver side. This technique is also known as Direction of Arrival (DOA) detection method. In this paper, the operation of target direction finding is performed and simulated using Keysight Advanced Design Studio (ADS) simulation tool. The six-port device is modelled in ADS using measured scattering parameters (S-parameters). To convert the received RF signal to baseband signal, RF power detector is also designed and simulated independently in ADS. The simulated results of each stage is discussed and presented in this paper. -
PublicationDirectional and wideband antenna for ground penetrating radar (GPR) applications( 2017-01-03)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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PublicationA 12 GHz LC-VCO Implemented with S’ shape Inductor using silicon-on sapphire substrate( 2022-12)M.S MispanA 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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PublicationThe design and analysis of high Q factor film bulk acoustic wave resonator for filter in super high frequency( 2021-12)
;Lam Hok LangChow Shi QiFiltering 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. -
PublicationAnalysis of different piezoelectric materials on the film bulk acoustic wave resonator( 2023-12)
;M. S. MispanN. Aiman SyahmiThe performance of film bulk acoustic wave resonators (FBAR) is greatly dependent on the choice of piezoelectric materials. Different piezoelectric materials have distinct properties that can impact the performance of FBAR. Hence, this work presents the analysis of three different piezoelectric materials which are aluminum nitride (AlN), scandium aluminum nitride (ScAlN) and zinc oxide (ZnO) on the performance of FBARs working at resonance frequencies of 6 GHz until 10 GHz. The one-dimensional (1-D) modelling is implemented to characterize the effects of these materials on the quality (Q) factor, electromechanical coupling coefficient (k2eff) and bandwidth (BW). It is determined that employing ScAlN in FBAR results in the highest Q factor, ranges from 628 to 1047 while maintaining a relatively compact area (25 μm × 25 μm) and thickness (430 nm to 720 nm). However, ScAlN yields the narrowest BW, measuring 0.11 GHz at 6 GHz, as opposed to AlN and ZnO, which exhibit broader bandwidths of 0.16 GHz and 0.23 GHz, respectively. -
PublicationCharacteristics of film bulk acoustic wave resonator using different electrode materials( 2021-07-21)
;Jing Y.W.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.1 -
PublicationFilm bulk acoustic wave resonator in 10-20 GHz frequency range( 2017-01-03)
;Nurul Izza Mohd Nor ;Siti Salwa Mat IsaThis paper presents the design and optimisation of film bulk acoustic wave resonator (FBAR) using nano electro mechanical systems (NEMS) technology in 10-20 GHz frequency band. The effect of thickness, width and length and damping factor of the FBAR are analysed. The air-gap FBAR are designed due its ability to achieve high quality (Q) factor in 10-20 GHz frequency band. The proposed designs achieve a constant electromechanical coupling coefficient for 10-20 GHz. Analysis shows the Q varies highly dependent on the damping factor. The results show that the proposed design achieves almost double the Q factor at 15 GHz and 20 GHz operation when compared to similar designs.1 13