ACES Publication Search
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| Title: | ACES Journal July 2015 Cover |
| File Type: | Journal Paper |
| Issue: | Volume: 30 Number: 7 Year: 2015 |
| Download Link: | Click here to download PDF File Size: 2344 KB |
| Title: | ACES Journal July 2015 Front/Back Matter |
| File Type: | Journal Paper |
| Issue: | Volume: 30 Number: 7 Year: 2015 |
| Download Link: | Click here to download PDF File Size: 114 KB |
| Title: | ACES Journal July 2015 Full |
| File Type: | Journal Paper |
| Issue: | Volume: 30 Number: 7 Year: 2015 |
| Download Link: | Click here to download PDF File Size: 14679 KB |
| Title: | Questioning Degree of Accuracy Offered by the Spectral Element Method in Computational Electromagnetics |
| Abstract: | In this paper, a comparison amongst the spectral element method (SEM), the finite difference method (FDM), and the first-order finite element method (FEM) is presented. For the sake of consistency, the comparison is carried out on onedimensional and two-dimensional boundary value problems based on the same measure of error in order to emphasize on the high accuracy gained by the SEM. Then, the deterioration in the accuracy of the SEM due to the elemental deformation is demonstrated. Following this, we try to answer the question: Do we need the high accuracy offered by the SEM in computational electromagnetics? The answer is supported by solving a typical, unbounded electromagnetic scattering problem in the frequency domain by the SEM. Domain truncation is performed by the well-known perfectly matched layer (PML). |
| Author(s): | I. Mahariq, H. Kurt, M. Kuzuoglu |
| File Type: | Journal Paper |
| Issue: | Volume: 30 Number: 7 Year: 2015 |
| Download Link: | Click here to download PDF File Size: 1023 KB |
| Title: | Interaction Between 3-T MRI Systems and Patients with an Implanted Pacemaker |
| Abstract: | In this paper, a transverse electro-magnetic (TEM) coil operating at 128 MHz in a 3-T magnetic resonance imaging system has been studied in terms of the interaction with patients with or without an implanted pacemaker. The pacemaker has been simulated as a copper box with a catheter constituted by an insulated copper wire with an uncapped tip and it has been placed inside either box or anatomical models of the thorax. Electromagnetic and thermal simulations have been performed by using finite difference time domain codes. The obtained results show that in the absence of the pacemaker, and for a radiated power producing in the box a whole body specific absorption rate (SAR) of 1 W/kg, that is a typical value for MRI examinations, the coil produces in the anatomical models peak temperature values lower than the limits issued by the International Electrotechnical Commission (IEC). In the presence of the pacemaker, temperature increments at the catheter tip in excess of those issued by the IEC standard are obtained when the MRI scanned area involves the pacemaker region. The 3-T coil produces lower SAR and temperature increments with respect to a 64-MHz (1.5-T system) birdcage antenna in patients with implanted pacemaker. |
| Author(s): | S. Pisa, E. Piuzzi |
| File Type: | Journal Paper |
| Issue: | Volume: 30 Number: 7 Year: 2015 |
| Download Link: | Click here to download PDF File Size: 898 KB |
| Title: | Fast Design of Jerusalem-Cross Parameters by Equivalent Circuit Model and Least-Square Curve Fitting Technique |
| Abstract: | Based on an equivalent circuit model, the least-square curve fitting technique is proposed to quickly design optimum values of geometrical parameters of a dual-band Jerusalem-cross element for arbitrarily specifying any dual resonant frequencies. The validity of the least-square curve fitting technique is checked by comparing geometrical parameters and dual resonant frequencies of six Jerusalem-cross grids obtained by the proposed technique with those obtained by the improved empirical model and measurement method. Design of dual-band Jerusalem-cross slots is also conducted by the proposed technique. Simulation results of reflection and dual resonant frequencies of Jerusalem-cross slots designed by the proposed technique are also validated by measurement data. |
| Author(s): | H.-Y. Chen, T.-H. Lin, P.-K. Li |
| File Type: | Journal Paper |
| Issue: | Volume: 30 Number: 7 Year: 2015 |
| Download Link: | Click here to download PDF File Size: 1859 KB |
| Title: | Pole Arc Skewing Analysis of Synchronous Reluctance Machine Using Discrete Method Combined with Winding Function Approach |
| Abstract: | The paper investigates the effect of pole arc skewing in synchronous reluctance machine on its torque ripple. To do this, the machine’s reluctances are calculated by using winding function approach (WFA). A numerical-based method is proposed for modeling the machine’s dynamic equations. The effect of rotor skewing and the winding type (single-layer or double layer) on the machine’s behavior and torque ripple are investigated. The results show that skewing the rotor is significantly effective in double-layer winding case and it is not a proper idea for machine with single-layer winding. The proposed method is capable of studying the voltage-fed machine’s behavior which is common in reality in comparison with current source-fed machine. Also, shorter calculation time and capability of studying parameter sensitivity are other advantages of the proposed method in comparison with finite element method (FEM). |
| Author(s): | P. Naderi, A. Shiri |
| File Type: | Journal Paper |
| Issue: | Volume: 30 Number: 7 Year: 2015 |
| Download Link: | Click here to download PDF File Size: 1268 KB |
| Title: | An Improved IEM2Mc Model for Surface Bistatic Scattering |
| Abstract: | In this paper, the IEM2Mc (integral equation model for second-order multiple s and complex-permittivity scattering media) model is modified in two aspects in bistatic scattering. Firstly, the full forms of the surface current terms in the Kirchhoff surface fields are reserved. Secondly, a transition function is used to estimate the Fresnel coefficients instead of the original expression. The simulating results of the improved IEM2Mc are compared with those of small perturbation method (SPM), Kirchhoff model (KA), and method of moment (MoM) for random rough surfaces scattering problems. It is shown that the improved IEM2Mc provides better predictions than the original form, especially for the large incident or scattering angle. |
| Author(s): | W. Zheng, Y. Leng, Q. Li |
| File Type: | Journal Paper |
| Issue: | Volume: 30 Number: 7 Year: 2015 |
| Download Link: | Click here to download PDF File Size: 364 KB |
| Title: | A Novel Slot Antenna with Reconfigurable Meander-Slot DGS for Cognitive Radio Applications |
| Abstract: | A new planar reconfigurable wideband slot antenna is proposed for cognitive radio (CR) applications in this paper. The wideband function is obtained by inserting a meander ?-shaped slot in the rectangular radiation patch. The reconfigurable characteristics with frequency diversity are achieved using four ideal switches integrated on the meander-slot defected ground structure (DGS) band stop filter embedded in the ground plane. The design procedures, impedance bandwidth, and radiation patterns are presented for explanation and examination of this antenna. The proposed reconfigurable slot CR antenna can work at three modes by controlling the switches at ON and OFF states. It operates over the frequency band between 1.52 GHz and 2.75 GHz (bandwidth of 57.6%), with two independent bands from 1.54 GHz to 2.28 GHz (38.7%) and 2.28 GHz to 2.85 GHz (22.2%). The measured results show that it has wide impedance bandwidth, multimode characteristics, and omnidirectional radiation patterns. |
| Author(s): | M. M. Fakharian, P. Rezaei, A. A. Orouji |
| File Type: | Journal Paper |
| Issue: | Volume: 30 Number: 7 Year: 2015 |
| Download Link: | Click here to download PDF File Size: 1578 KB |
| Title: | Design and Optimization of a CPW-Fed Tri-Band Patch Antenna Using Genetic Algorithms |
| Abstract: | This paper investigates a compact tri-band patch antenna fed by a coplanar waveguide (CPW) line for the applications of WiFi, WiMAX and HiperLAN. The dimensions of the proposed antenna are optimized using genetic algorithms (GAs). The antenna is designed to function at three different resonant frequencies which are 2.46 GHz, 3.56 GHz and 5.5 GHz. Numerical results for the return loss, radiation pattern and gain of the antenna are presented. The antenna structure was fabricated, and the measured results have a good agreement with the full-wave simulated ones. |
| Author(s): | K. Fertas, H. Kimouche, M. Challal, H. Aksas, R. Aksas, A. Azrar |
| File Type: | Journal Paper |
| Issue: | Volume: 30 Number: 7 Year: 2015 |
| Download Link: | Click here to download PDF File Size: 2394 KB |
| Title: | Narrow Band, Sharp Roll-Off Rejection Frequency Selective Surface Based on Substrate Integrated Waveguide |
| Abstract: | In this paper, a novel frequency selective surface which has a narrower passband and sharper rolloff rejection than the other single layer designs, is presented. Also, it has better independency from angle and polarization of incident plane wave. In this design a ring loop is placed on a cylindrical cavity of substrate integrated waveguide (SIW). Because of the most compatibility between loop and the electric fields of cylindrical cavity, minimum insertion loss and narrow passband are achieved. |
| Author(s): | M. S. Samani, R. S. Shirazi, G. Moradi |
| File Type: | Journal Paper |
| Issue: | Volume: 30 Number: 7 Year: 2015 |
| Download Link: | Click here to download PDF File Size: 630 KB |
| Title: | Hybrid MLFMA/MLACA for Analysis of Electromagnetic Scattering from Inhomogeneous High-Contrast Objects |
| Abstract: | An efficient hybrid method is proposed to analyze the electromagnetic scattering from the composite structures comprising PEC and inhomogeneous high-contrast dielectric materials with the volume-surface integral equation (VSIE) approach, which uses the main framework of the multilevel fast multipole algorithm (MLFMA) but adopts the multilevel adaptive cross approximation algorithm (MLACA) and the equivalent dipole-moment (EDM) to deal with part of the “strong” interaction of MLFMA. Numerical results are presented to demonstrate the accuracy and efficiency of the proposed scheme. |
| Author(s): | Y. L. Hu, Z. H. Fan, D. Z. Ding, R. S. Chen |
| File Type: | Journal Paper |
| Issue: | Volume: 30 Number: 7 Year: 2015 |
| Download Link: | Click here to download PDF File Size: 430 KB |
| Title: | Octave-Band Monopole Antenna with a Horseshoe Ground Plane for Wireless Communications |
| Abstract: | In this manuscript, a new design of octaveband monopole antenna with multi-resonance characteristic is presented .The antenna consists of a fork-shaped radiating patch with three pairs of teeth, a feed-line and a horseshoe ground plane. Simulated and measured results show that the antenna design exhibits an operating bandwidth (VSWR<2) from 2 to 20 GHz, which provides a wide usable fractional bandwidth of more than 160%. The proposed antenna has a symmetrical structure, therefore displays a good omnidirectional radiation pattern even at higher frequencies. The designed antenna has a very small size of 15×17 mm2 and the impedance bandwidth of the designed antenna is higher than the other antennas reported in the literature to date. The proposed antenna configuration is simple, easy to fabricate and can be integrated into UWB systems. |
| Author(s): | M. M. Abdollahi, N. Ojaroudi, M. Mehranpour, F. Ghiasvand |
| File Type: | Journal Paper |
| Issue: | Volume: 30 Number: 7 Year: 2015 |
| Download Link: | Click here to download PDF File Size: 1023 KB |
| Title: | Compact Wideband Bandpass Filter Using Improved Triple-Mode Resonator with Broad Upper Stopband |
| Abstract: | ? A triple-mode microstrip square ring short stub-loaded stepped impedance resonator (SIR) is proposed for the design of bandpass filters (BPFs). The resonator possesses three resonances over the wide frequency band, which can be employed to implement a BPF with flat response. This kind of the filter is able to control spurious response by changing the structure of the resonator. For validation, a triple-mode BPF with central frequency of 2.55 GHz has been designed, fabricated and measured. Good agreement is observed between measured and simulated results. |
| Author(s): | D. Li, Y. Zhang, K. Xu, K. Song, J. L.-W. Li |
| File Type: | Journal Paper |
| Issue: | Volume: 30 Number: 7 Year: 2015 |
| Download Link: | Click here to download PDF File Size: 671 KB |
| Title: | A Parallel Implementation for the Time-Domain Analysis of a Rectangular Reflector Antenna Using OpenMP |
| Abstract: | This paper presents and evaluates a parallel time domain analysis of a rectangular reflector on multicores machine. Rectangular reflector antennas have motivated the time-domain analysis of electromagnetic scattering problems. The asymptotic time domain physical-optics (TDPO) is applied to the analysis of a rectangular reflector illuminated by a Gaussian-impulse. It is a numerical technique used in computational electrodynamics. The effects of time-delayed mutual coupling between points on the surface will be ignored to avoid the numerical limitations found in other conventional time-domain techniques such as interpolation error, numerical dispersion error, etc. As a result, the scattered signals at the specular reflection point, at the edges, and at the corners can be clearly distinguished. Furthermore, this paper evaluates and compares the performance of the sequential time-domain analysis against the parallel time-domain analysis on multicores machine. |
| Author(s): | G. M. Sami, K. Ragab |
| File Type: | Journal Paper |
| Issue: | Volume: 30 Number: 7 Year: 2015 |
| Download Link: | Click here to download PDF File Size: 896 KB |
| Title: | A New Design of Cell Phone Body for the SAR Reduction in the Human Head |
| Abstract: | In this paper, a new design of cell phone body is presented to reduce the specific absorption rate (SAR) in the human head. The SAR in the human head and total absorbed power by the cell phone user are calculated along with antenna performances in terms of radiation efficiency and directivity to validate the effects of cell phone body. It is found that the SAR in the head is reduced significantly for both the lower and upper global systems for mobile (GSM) frequency band. The new mobile body provides 63.8% reduction in the SAR at 900 MHz and 69.2% reduction at 1800 MHz in comparison of without mobile cover configuration. Moreover, the mobile casing improves the radiation efficiency 6% and 7% in the lower and the upper GSM frequency band respectively. |
| Author(s): | M. I. Hossain, M. R. I. Faruque, M. T. Islam |
| File Type: | Journal Paper |
| Issue: | Volume: 30 Number: 7 Year: 2015 |
| Download Link: | Click here to download PDF File Size: 1471 KB |
| Title: | A New Multifractal Geometry for Design of Frequency Selective Surfaces with Dual Band Response |
| Abstract: | In this paper, we proposed a new multifractal geometry for design of frequency selective surfaces (FSS) with dual band response. The proposed new geometry is called Ericampos. The main advantage of the proposed geometry is to design dual band FSS and makes it flexible in terms of controlling resonance and bandwidth. In addition, the proposed structure is easy to implement. The validation of the proposed structure was initially verified through simulations in a commercial software and then the structure was built and experimental results were obtained. A good agreement between numerical and experimental results is observed. The structure shows angular stability and polarization independence. |
| Author(s): | E. C. Braz, A. L. P. S. Campos |
| File Type: | Journal Paper |
| Issue: | Volume: 30 Number: 7 Year: 2015 |
| Download Link: | Click here to download PDF File Size: 232 KB |
| Title: | Analysis of Edge Terminated Wide Band Biconical Antenna |
| Abstract: | A finite length biconical antenna has standing waves existing due to its abrupt discontinuity at the terminals and results in band width limitation. An appropriate termination of these terminals can enhance its bandwidth to a considerable extent and make it truly wide band. A finite biconical antenna with its edges terminated in thick loop (circular) is proposed and its radiation characteristics are analyzed for different values of ‘?r’. Where ‘?’ is the wave number and ‘r’ is the length of the antenna. Compact antennas for ultra wide band (UWB) and above are in demand for modern communications and the proposed antenna meets the wide band requirement at UWB and above such as X, Ku, K bands with very low return loss. |
| Author(s): | C. S. Rao, A. Sudhakar |
| File Type: | Journal Paper |
| Issue: | Volume: 30 Number: 7 Year: 2015 |
| Download Link: | Click here to download PDF File Size: 1183 KB |