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Applied Electromagnetics (APACE), 2010 IEEE Asia-Pacific Conference on

Date 9-11 Nov. 2010

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Displaying Results 1 - 25 of 65
  • [Front cover]

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    Freely Available from IEEE
  • [Front matter]

    Page(s): i - xxv
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  • The role of computer graphics cards in advancing electromagnetics education

    Page(s): 1 - 2
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (135 KB) |  | HTML iconHTML  

    Over the past decade video cards have grown from simple interfaces to the monitor to powerful computational engines. The rise in advanced graphics for games has driven the manufacturers of video cards to a more rapid development cycle producing computationally powerful chips. The current generation of advanced graphical processing units (GPU's) has over four times the number of transistors than the standard dual core CPU's. The vast majority of the transistors in these GPU's are dedicated to the calculations required by high end video games. Recent developments in programming languages has allowed the processing power of these chips be used for general mathematic processing. With the current development cycle of graphics processors outpacing their CPU counterparts at every twelve months, these chips only aim to get even more powerful in the future. One of the major problems encountered with teaching electromagnetics is simulating devices that are being taught. Often the analytical formulas will be discussed and simulations will be assigned as homework. Since the simulation time required even for smaller problems is prohibiting for demonstrations in class. Harnessing the power of the video cards for electromagnetic simulations allows the time required to analyze the devices being taught to be reduced from minutes down to seconds. Simple graphical user interfaces (GUI's) have been built to demonstrate the operation of simple electromagnetic devices such as patch antennas, microstrip filters, and printed dipoles with simulation times of under 30 seconds. This has been accomplished by interfacing a Matlab GUI with a GPU based FDTD simulator. With these GUI's the instructor or students can vary all the parameters of the devices and examine the effects in a matter of seconds. This allows the instructor to show what happens in a device when it is designed a certain way rather than just talk about the formulas in an abstract sense. The students can also use these progr- - ams to explore the operation of these devices. View full abstract»

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  • Simple design approach of dual-band printed antenna using graphical approximations

    Page(s): 1 - 4
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (391 KB) |  | HTML iconHTML  

    Dual operation antennas have gained importance in the development of compact structures. In this paper, a simple approach using graphical approximations is presented for the design of a dual-band antenna. An example of dual-band operation is for the GPS (Global Positioning System) satellite reception with frequencies in the L-band. The chosen antenna is the rectangular microstrip patch having two equal size radiating elements, each operates at a different frequency within the L-band. A mathematical software is used for computing and correlating the relevant design formulae. View full abstract»

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  • Evaluation on optimum geometrical of linear node array for self-organization in a wireless sensor network

    Page(s): 1 - 5
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (231 KB) |  | HTML iconHTML  

    A novel approach which combines an adaptive linear antenna array and a non-linear function of particle swarm methodology has been developed to estimate the performance of antenna gain in the presence of sensor node geometry location uncertainties. The randomness of sensor nodes geometry location can produce higher energy consumption as it permits the generation of high peaks in radiation beampattern performance. It is shown in simulations that the method is powerful in term of required main beam angle and side lobe level reduction. Results indicate an improve performance in term of radiation beampattern and motivate exploiting this newly-developed optimum method in node geometrical location strategies of WSNs. View full abstract»

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  • Design and simulation of a Sierpinski Carpet Fractal PIFA for WLAN and HiperLAN application

    Page(s): 1 - 4
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (247 KB) |  | HTML iconHTML  

    This paper describes the design and simulation of Sierpinski Carpet Fractal Planar Inverted F Antenna (PIFA) for WLAN and HiperLAN applications. Simulation of antenna is carried out using CST software; on a FR4 board with a substrate thickness of 1.6 mm and relative permittivity of 4.7. The antenna achieved satisfactory 10-dB impedance bandwidths, between the frequencies of 2341-2812 MHz and 5360-6154 MHz, which applies to Bluetooth, WLAN and HiperLAN applications. Performance of the proposed antenna is discussed in terms of reflection coefficient (S11), radiation patterns, and gain. Analysis of the result indicated that the number of resonances increases linearly with the number of iteration. On the other hand, bandwidth produced is also largest at the highest resonance point. In the final design, the proposed first fractal iteration produced the desirable trade-off between bandwidth adequacy and resonating at the desired frequencies. View full abstract»

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  • Miniaturized microwave modified Koch fractal Hairpin Filter with harmonic suppression

    Page(s): 1 - 4
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (308 KB) |  | HTML iconHTML  

    Designing a filter with harmonic suppression capability without adding any external filtering capacitors or notch filter is a big challenge. The paper presents the design of a compact microstrip bandpass filter having integrated harmonic suppression capability. The filter operates at a center frequency of 900 MHz. The structure chosen is the Hairpin Filter. The conventional hairpin is modified by integrating with Koch fractal shaped structure for miniaturisation and harmonic suppression capability. The filters were simulated and optimized using electromagnetic simulation software. Integration of fractal shaped structure into microstrip filters can be used as harmonic suppressor. In addition, reduction in size is also attainable. Second harmonic suppression of up to -35 dB is achieved for the fractal shaped Hairpin Filter, FSF, design. View full abstract»

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  • Reduced size harmonic suppressed fractal dipole antenna with integrated reconfigurability

    Page(s): 1 - 4
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (305 KB) |  | HTML iconHTML  

    Reduced size frequency reconfigurable fractal dipole antenna with harmonic suppression capability is presented in this paper. The proposed antenna consists of a narrow band radiating element, stub-filters and taper balun, producing harmonic suppression characteristics. In order to investigate the antenna performance, an extensive simulation (by CST and HFSS) and measurement works have been carried out. This technique is suitable for creating reconfigurable antenna with harmonic suppression or for single band antennas. View full abstract»

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  • Preliminary design of rectangular nano-antenna at PHz

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    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (271 KB) |  | HTML iconHTML  

    This paper presents preliminary investigation and design of a rectangular nano-antenna that exhibits pentahertz (PHz) radiation. A plasmonic material is proposed as the substrate to be used for the antenna. The configuration chosen for the antenna radiating element is the rectangular structure. Numerical simulation based on FDTD has been performed on the designed antenna with varying substrate thickness. It was found that the antenna can operate well at the desired PHz frequency. View full abstract»

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  • A novel RF tunable impedance matching network for correcting the tested result deviation from simulated result

    Page(s): 1 - 4
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (378 KB) |  | HTML iconHTML  

    In practical situation of designing a power amplifier, inaccurate model, tolerance of the components, manufacture tolerance, variation in substrate dielectric could make the measurement result different from simulated result. For correcting those errors, a novel tunable matching network with simple structure in load matching network is presented in this paper. Two variable capacitors are integrated in the load as a part of the matching network. The output impedance could be modified by changing the values of these two capacitors. By this method, 8 impedance points around the original simulated maximum PAE (Power added efficiency) point are chosen and measured to get the maximum PAE. A class B power amplifier at one-tone frequency 2.14 GHz with this structure is designed, fabricated and tested for demonstrating the method of correcting. The measurement result before correcting is different from the simulated one. After tuning these two capacitors in load matching network, the PAE is increased by 21.8% from 33.4% to 55.2%, which more agrees with the simulated results. View full abstract»

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  • Antenna with DGS for improved performance

    Page(s): 1 - 4
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (249 KB) |  | HTML iconHTML  

    A recently introduce technique for improving cross-polarisation in microstrip antenna is to employ defected ground structure (DGS). In this paper, the experimental investigations have been carried out on a microstrip antenna that has been embedded with a DGS element having V-slot shape. It was found that the undesired cross-polarisation has been reduced while the impedance bandwidth has broadened. View full abstract»

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  • Parametric investigation of multilayer ring resonator filters

    Page(s): 1 - 4
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (868 KB) |  | HTML iconHTML  

    This paper reports a parametric investigation of a compact UWB bandpass filter based on multilayer ring resonators (MRR). With the strip width, loop length and gap size fixed, the scattering parameters of the filter were simulated using CST electromagnetic simulator for various cases of differing substrate thickness and permittivity, and against the number of resonators and their orientation. Our results show that when the substrate permittivity was increased, the bandwidth and the center frequencies lowered. The bandwidth can be restored, however, by increasing the ring orientation from 90° to 180°. Decreasing the substrate thickness, however, increases the bandwidth and the return loss but the thickness below than 0.2 mm decreases the return loss. The substrate thickness also affected the insertion loss characteristics - thicknesses of more than 0.8 mm would give too much insertion loss in the passband. The return loss improved by increasing the number of rings. The output feedline position also affect the position and number of transmission zeros. Odd ring numbers will give transmission zeros at either side of the passband depending on the coupling sense, while even ring numbers can either produce zeros on both sides or none at all. View full abstract»

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  • The calculation of field strength for DTV receiver by Rec. ITU-R P.1546

    Page(s): 1 - 4
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (2342 KB) |  | HTML iconHTML  

    We propose the methodology of field strength prediction for a digital television (DTV) receiver by virtue of Rec. ITU-R P.1546. The curves shown in this Rec. represent the point-to area field strength for 1kW effective radiated power in the 30 MHz ~ 3000 MHz. Some computed results are illustrated here from the formulation of field strength for DTV receiver. It was shown that the error of field strength value for dense urban area (R = 30 m) is in the range of about 6.8 ~ 11.5% compared with the Okumura-Hata model under some conditions. In addition comparison of service distance between analog and digital TV receivers has been also illustrated. The presented method provides the predicted values of field strength for TV receiver whether transmission quality can be assured or not, and it can be also used to get the protection ratio or separated distance for frequency sharing in the same or adjacent band. View full abstract»

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  • The improvement of VCO performance based upon in/out common frequency tuning

    Page(s): 1 - 4
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1906 KB) |  | HTML iconHTML  

    In this paper, we presented a K-band Voltage Controlled Harmonic Oscillator (VCHO) with novel structure. The proposed VCHO is a structure of two hair-pin resonators placed on input and output of active device. By using in/out common frequency tuning structure, the VCHO produced some advantages of the enhanced characteristics of fundamental frequency suppression as well as the improved second harmonic output power. According to measurement results, it has been shown that a VCHO provide the output power of -2.41 dBm, fundamental frequency suppression of -21.84 dBc, and phase noise of -101.44 dBc/Hz @ 100 kHz. In addition, output frequency range of 10.58 MHz could be obtained with a power variation of +/-0.19 dB over its frequency range with respect to the bias voltage from 0 to -10 V for the varactor diode. View full abstract»

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  • An active uplink photonic antenna

    Page(s): 1 - 4
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (484 KB) |  | HTML iconHTML  

    This paper presents a wideband photonic antenna consisting the laser diode, matching circuit, RF amplifier and microstrip patch antenna are fabricated and connected together to perform in uplink system. Laser driver is used to supply the dc biasing for the laser. Lastly, the LD-matching circuit, RF amplifier and antenna were arrange together and connected to perform the wireless uplink system. The simulated and measured results are presented and discussed. These results show useful photonic antenna design that achieves relatively wide bandwidth and has potential to be applied in RoF technology. View full abstract»

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  • The effects of foliage on 5.8GHz Broadband Fixed Wireless Access (BFWA)

    Page(s): 1 - 5
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (542 KB) |  | HTML iconHTML  

    This paper investigates the foliage effect on fixed wireless links based on IEEE 802.11a standard operating at frequency 5.8GHz of Unlicensed National Information Infrastructure (UNII) bands. Based on the studies of the measured received signal profiles under two different links, it is observed that the foliage obstruction gives significant effects on the link performance. The results from measurements performed are discussed and presented in term of their statistical distribution. View full abstract»

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  • Hydraulic pressure distribution for pipeline networks by wireless sensor networks

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    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (706 KB) |  | HTML iconHTML  

    In this paper, we propose a new application of wireless sensor networks for real time monitoring of water pressure distribution in urban areas. Our application consists of a number of clustered sensor nodes that measure the pressure in water pipelines. Sensor nodes communication is based on the IEEE802.15.4 standard by the help of Zigbee modules. The data is collected in 15-minute periods and is sent to the control center via GPRS. The main purpose of this application is to solve the problem of unbalanced water pressure distribution in cities. We setup smart cyclic sleep modes that made our system, energy efficient and very low-power consumption. We implemented this application in city of Mashhad. We analyzed water pipeline system pressure measurement in several periods, which gave us the optimum pressure needed for an area based on its population, longitude and consumption pattern. We concluded that our solution will improve and eliminate the city water pressure distribution problem. View full abstract»

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  • Performance of a configurable microstrip filter using triple mode resonator and RF-MEMS switches

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    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (275 KB) |  | HTML iconHTML  

    This paper presents a configurable bandpass filter using commercial RF MEMS switches in a compact triple-mode resonator. Before designing the filter, the effect of using the RF-MEMS switch on the resonant frequency of a simple hairpin resonator is studied. The insertion loss of the switch is measured. A three-pole Chebyshev bandpass filter with a fractional bandwidth of 20% at a center frequency of 0.95 GHz is designed and fabricated. With a biasing voltage of 25 V, the center frequency of the filter can be switched to 0.70 GHz. The fractional bandwidth of the filter changes from 20% to 10%. This filter exhibits low harmonic response in the stopband. View full abstract»

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  • A new multi-slot and multi-level coding technique for high capacity communication system

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    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (227 KB) |  | HTML iconHTML  

    A new multi-slot and multi-level coding technique for high capacity communication system, known as Multi Slot Amplitude Coding (MSAC) is presented. This technique offers better flexibility in terms of defining the symbol based on time slot and signal level in order to generate more unique symbols as a line code with better clock information since all the symbols have zero level (return-to-zero) at the beginning. A set of mathematical equations have been established to relate the parameters of MSAC symbol properties. Theoretical analysis to evaluate the performance of this technique based on the number of slot and the number of signal level against conventional Time Division Multiplexing (TDM), multilevel Mary signaling, and Duty Cycle Division Multiplexing (DCDM) are discussed. The comparison shows that MSAC technique is capable to maximize the number of supportable tributaries with better utilization of the slot and the signal level. View full abstract»

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  • Wide-band rectangular dielectric resonator antenna design

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    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (699 KB) |  | HTML iconHTML  

    In this paper a novel design procedure to obtain wideband and small size dielectric antennas using high dielectric constant material is described. It is shown that by selecting the resonator shape and creating a notch on the dielectric resonator, it is possible to design rectangular dielectric resonator antenna which compact size and wide frequency coverage. Simple formulas are presented to illustrate the design procedure and allow a quick dimensioning of the antenna. Utilizing the proposed configuration and skillfully varying its aspect ratio, an appropriate structure is obtained that illustrates more than 47.03% impedance bandwidth (for VSWR<; 2) at 4.39 to 7.09GHz frequency band. View full abstract»

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  • A novel P-shape dielectric resonator antenna for wideband application

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    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (495 KB) |  | HTML iconHTML  

    A novel P-shape wideband dielectric resonator antenna design is presented for wireless application in this paper. It is described by using a P-shape dielectric resonator with high dielectric constant (εr = 30) that is placed on the truncated ground plane, a wideband impedance bandwidth of about 64% (for VSWR≤2), covering the frequency range of 3.40-6.58GHz is achieved. Analysis of the proposed antenna is performed using CST Microwave Studio software. View full abstract»

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  • Multiband microstrip antenna for RFID application

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    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (989 KB) |  | HTML iconHTML  

    A Multiband microstrip antenna for RFID application is proposed in this paper. The antenna design consists of two substrates with EMC feeding technique. The antenna design uses FR4 substrate and has dimension of 118 × 120 mm. Both simulation and measurement results show multiband characteristic at frequency bands 433 MHz, 923 MHz and 2.45 GHz. View full abstract»

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  • A miniaturized dual-frequency Wilkinson power divider using defected ground structure

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    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (434 KB) |  | HTML iconHTML  

    In this paper, we apply a defected ground structure (DGS) to design a compact dual-frequency Wilkinson power divider (WPD). As the necessary area for dual-frequency Wilkinson power divider has a considerable increment toward single frequency WPD, we have to reduce its size especially in lower frequencies. With using dumbbell DGS, both designed operating frequencies are significantly lowered and consequently 49% size reduction for both operating frequencies is achieved. Simulated and measured results are presented and show good agreement. View full abstract»

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  • Coaxial feed Archimedean spiral antenna for GPS application

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    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (515 KB) |  | HTML iconHTML  

    This work highlights the design, simulation and analysis of an Archimedean spiral antenna (ASA) for GPS application. The antenna was fed using coaxial feed and a prototype was fabricated on FR4 of dielectric constant, εr = 4.9 with thickness of 1.54 mm while the center frequency was 1.575 GHz. The design and simulation of the ASA were carried out b y using commercial electromagnetic simulator, CST. The prototype was fabricated, measured and analyzed using Vector Network Analyzer (VNA), ZVA40. 2D radiation pattern was obtained by using antenna training system, ED3200. It was observed that the measured and simulated values of the parameters of the ASA were close with each other. The frequency independent of the ASA was achieved by having the same values of inner radius r, width of arm w and the spacing, s between each turn of the ASA. The radiation pattern obtained illustrated an omni-directional pattern. View full abstract»

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  • Quarter wavelength matching in dielectric resonator bandpass filter

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    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (296 KB) |  | HTML iconHTML  

    This paper focuses on the analysis to find suitable locations to place dielectric resonators on microstrip transmission line in order to obtain a high coupling effect. A novel design of an X-Band bandpass filter from a combination of a simple transmission line and three cylindrical dielectric resonators are used in this analysis. The three dielectric resonators are same in permittivity and radius of 60 and 2.55 mm, respectively. This analysis found that the coupling effect can be maximized by placing dielectric resonators a distance of quarter or half wavelength from each other. View full abstract»

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