Now showing 1 - 10 of 19
  • Publication
    Remazol orange dye sensitized solar cell
    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.
  • Publication
    Development 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%.
  • Publication
    Directional and wideband antenna for ground penetrating radar (GPR) applications
    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.
  • Publication
    The design and analysis of high Q factor film bulk acoustic wave resonator for filter in super high frequency
    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.
  • Publication
    Analysis on Square and Circular Inductor for a High Q-Factor Inductor
    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.
      2  22
  • Publication
    Target 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.
      16  1
  • Publication
    The Design and Analysis of High Q Factor Film Bulk Acoustic Wave Resonator for Filter in Super High Frequency
    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.
      2
  • Publication
    Analysis of Different Piezoelectric Materials on the Film Bulk Acoustic Wave Resonator
    ( 2023-12-01) ; ; ;
    Mispan M.S.
    ;
    Syahmi N.A.
    The 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 (k2 eff) 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.
      1  23
  • Publication
    Development of six-port baseband processing system for short range radar based sensor
    ( 2017-01-03)
    Nurul Ainun Zulkifli
    ;
    ; ;
    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.
      2  21
  • Publication
    Analysis of different piezoelectric materials on the film bulk acoustic wave resonator
    ( 2023-12) ; ; ;
    M. S. Mispan
    ;
    N. Aiman Syahmi
    The 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.
      1  27