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Title: ACES Journal November 2014 Cover
File Type: Journal Paper
Issue:Volume: 29      Number: 11      Year: 2014
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Title: ACES Journal November 2014 Front/Back Matter
File Type: Journal Paper
Issue:Volume: 29      Number: 11      Year: 2014
Download Link:Click here to download PDF     File Size: 110 KB

Title: ACES Journal November 2014 Full
File Type: Journal Paper
Issue:Volume: 29      Number: 11      Year: 2014
Download Link:Click here to download PDF     File Size: 10739 KB

Title: Metal Grip Grating on Grounded Dielectric Slab and PEC/PMC Shielded Interconnect: Modal Relationships
Abstract: This paper employs the spectral domain approach for full wave analysis of metal strip grating on grounded dielectric slab and microstrips shielded with either Perfect Electric Conductor (PEC) or Perfect Magnetic Conductor (PMC) walls. The modal relations between these structures are revealed by exploring their symmetries. It is derived analytically and validated numerically that all the even and odd modes of the latter two (when they are mirror symmetric) find their correspondence in the modes of metal strip grating on grounded dielectric slab when the phase shift between adjacent two unit cells is 0 or ?. Extension to non-symmetric case is also made. Several factors, including frequency, grating period, slab thickness and strip width, are further investigated for their impacts on the effective permittivity of the dominant mode of PEC/PMC shielded microstrips. It is found that the PMC shielded microstrip generally has a larger wave number than the PEC shielded microstrip.
Author(s): K. Chen, J. Song, T. Kamgaing
File Type: Journal Paper
Issue:Volume: 29      Number: 11      Year: 2014
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Title: Numerical Investigation of Monitoring Antenna Influence on Shielding Effectiveness Characterization
Abstract: This paper deals with an impact of receiving antenna placed in a metal enclosure on an electromagnetic field distribution within the enclosure, and thus on its shielding effectiveness. In an experimental setup, a frequently used tool for measuring the electromagnetic field level at certain points within the enclosure is a dipole antenna connected to a measuring instrument via a coaxial cable. For modeling a coupling between the electromagnetic field and antenna in the protective enclosure we use the Transmission-Line Matrix (TLM) method, enhanced with the compact wire model. The numerical model is verified through comparison with the available experimental results and then used to investigate the influence of physical dimensions of dipole antenna and its cable connection on the detected level of shielding effectiveness.
Author(s): T. Cvetkovic, V. Milutinovic, N. Doncov, B. Milovanovic
File Type: Journal Paper
Issue:Volume: 29      Number: 11      Year: 2014
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Title: Development of a Broadband Substrate Integrated Waveguide Cavity Backed Slot Antenna Using Perturbation Technique
Abstract: A novel method for bandwidth enhancement of Substrate Integrated Waveguide (SIW) cavity-backed slot antenna is introduced for a single element and an array configuration. Using a corner cut in the SIW square cavity, resonant frequency of two degenerate TE210 and TE120 modes of a square cavity are separated and impedance bandwidth is improved. The simulated and measured results of the antennas show at least 140% and 220% wider bandwidth compared to the bandwidth of a conventional single cavity antenna for single and two element array antennas, respectively. The presented antennas provide a few advantages including low profile, light weight, easy fabrication with low cost and convenient integration with planar circuits.
Author(s): E. Baghernia, M. H. Neshati
File Type: Journal Paper
Issue:Volume: 29      Number: 11      Year: 2014
Download Link:Click here to download PDF     File Size: 1204 KB

Title: Using the Best Uniform Approximation with Compression for Efficient Computation of Monostatic Scattering
Abstract: The best uniform approximation method hybridized with Singular Value Decomposition (SVD) is proposed to reduce the time requirement for computation of monostatic Radar Cross Section (RCS). In contrast to our previous work, the traditional best uniform approximation technique is applied to compute the key excitation vectors instead of electric current vectors. Reduction of the number of multiple excitation vectors can lead to significantly reduced computation time. Furthermore, with low-rank property, the key excitation vectors could be further compressed by SVD, resulting in a more efficient method. Numerical results demonstrate that the proposed method is efficient for monostatic RCS calculation with high accuracy.
Author(s): Z. Liu, S. He, X. Zhang, Y. Liu, Y. Zhang
File Type: Journal Paper
Issue:Volume: 29      Number: 11      Year: 2014
Download Link:Click here to download PDF     File Size: 603 KB

Title: Fabrication of a Novel Diplexer Using Folded Open-Loop Ring Resonators and Microstrip Lines
Abstract: A simple and novel low-loss diplexer with two folded Open-Loop Ring Resonators (OLRRs) that couple three microstrip lines is proposed. The first passband and second passband of the designed diplexer could be easily and accurately shifted to a desired frequency and construct the bandpass filters by adjusting the physical dimensions of the OLRRs. These results suggested that the proposed diplexer had the frequency-adjustable characteristics. The longer OLRR is placed between the upper and middle microstrip lines to generate a 2.4 GHz resonant frequency and the shorter OLRR is placed between the middle and lower microstrip lines to generate a 5.2 GHz resonant frequency. By adjusting the positions of the two OLRRs, the resonant frequencies can be tuned.
Author(s): C.-M. Chen, S.-J. Chang, C.-F. Yang
File Type: Journal Paper
Issue:Volume: 29      Number: 11      Year: 2014
Download Link:Click here to download PDF     File Size: 722 KB

Title: High Gain Dielectric Loaded Exponentially Tapered Slot Antenna Based on Substrate Integrated Waveguide for V-Band Wireless Communications
Abstract: The conception of Substrate Integrated Waveguide (SIW) technology and Exponentially Tapered Slot (ETS) antenna are together used to design a high gain, and efficient planar dielectric loaded antenna for V-band wireless communications. To increase the gain of the antenna, a dielectric loaded portion is used in front of the antenna which works as a dielectric guiding structure and SIW is used to feed the proposed antenna. The dielectric loaded ETS antenna and compact SIW feed are fabricated on a single substrate, resulting in low cost and easy fabrication. The antenna with elliptical shaped dielectric loaded is fabricated using printed circuit board process. The measured gain of the single element antenna is 10.2 dB, while the radiation efficiency of 96.84% is obtained at 60 GHz. The Y-junction SIW power divider is used to form a 1×2 array structure. Measured gain of the 1×2 array antenna is 11.2 dB, while the measured radiation pattern and gain are almost constant within the wide bandwidth of the antenna.
Author(s): S. Ramesh, T. R. Rao
File Type: Journal Paper
Issue:Volume: 29      Number: 11      Year: 2014
Download Link:Click here to download PDF     File Size: 573 KB

Title: Modified Broadband Half Mode Substrate Integrated Waveguide Cruciform Coupler
Abstract: In this paper, a cruciform coupler with Half Mode Substrate Integrated Waveguide (HMSIW) structure is presented. The prototype coupler consists of four half mode SIW structures, which are crossing each other at right angles. Also, two metallic posts are inserted in free section of junction in order to make coupling properties. Compact size and broadband operation are the features of this coupler. The size of coupler is reduced 24% in comparison to previous HMSIW cruciform couplers. A fractional bandwidth of about 35% is obtained. The coupler is designed and simulated by HFSS13. Here, the simulation results are compared with experimental results.
Author(s): Z. Mansouri, M. Kishihara, F. B. Zarrabi, F. Geran
File Type: Journal Paper
Issue:Volume: 29      Number: 11      Year: 2014
Download Link:Click here to download PDF     File Size: 522 KB

Title: An Improved Combination of IE-ODDM and MLFMA
Abstract: Domain decomposition methods are efficient for analyzing scattering problems with large-scale structures. In the present paper, an improved combination of Overlapped Domain Decomposition Method of Integral Equations (IEODDM) and Multilevel Fast Multi-pole Algorithm (MLFMA) is developed. Amount of independent MLFMA progresses of sub-domains are departed and re-integrated, such that the total CPU time of coupled effects in IE-ODDM can be saved. The proposed method developed minimal-completed sub-trees of sub-domains to reduce redundant aggregations of the MLFMA process blended in IEODDM. Numerical results and comparisons with the original method are provided, which suggest that the proposed combination integrates MLFMA with IE-ODDM better than the original combined method, and it can greatly improve the computational efficiency of coupled effects in IEODDM.
Author(s): J. Hu
File Type: Journal Paper
Issue:Volume: 29      Number: 11      Year: 2014
Download Link:Click here to download PDF     File Size: 597 KB

Title: Real-Time Implementation of UWB-OFDM SAR Imaging System Using Shared Memory Based FPGA
Abstract: This paper presents a novel technique for FPGA based implementation of highresolution SAR system using UWB-OFDM architecture. Greater computation time and larger memory requirement are the main difficulties in processing large amount of raw data in real-time SAR imaging. Significant part of the computation time is related to range and azmuth compression of raw SAR data which in turns heavily depends on computing FFT, IFFT and complex multiplication. A shared memory based FPGA model is developed using Xilinx block-set that provides real-time SAR imaging with higher accuracy and less computation time. The design procedures are straightforward and can be applied to practical SAR system for real-time imaging. The model is designed as hardware co-simulation using Xilinx system generator and implemented on Xilinx Virtex-6 ML605 FPGA.
Author(s): M. A. Hossain, I. Elshafiey, M. A. S. Alkanhal
File Type: Journal Paper
Issue:Volume: 29      Number: 11      Year: 2014
Download Link:Click here to download PDF     File Size: 1474 KB

Title: Normal Directionaly NURBS Arithmetic of Conformal PML
Abstract: Conformal Perfectly Matched Layer (PML) is a high-efficiency absorbing boundary condition for the finite element analysis of electromagnetic fields. Accurate calculation of normal direction of conformal PML is essential for the geometric modelling of conformal shell elements and constitutive parameters of conformal PML, especially for sophisticated and arbitrary shape scatterers. Consequently, a Non-Uniform Rational B-Splines (NURBS) arithmetic is proposed for describing the conformal surface accurately in this study. Based on the NURBS arithmetic, four weighted average formulas are presented for calculating the common normal direction of adjacent surface elements of conformal shell. Numerical experiments show the availability of NURBS arithmetic and precision of weighted average formulas in the geometrical modelling of conformal PML.
Author(s): Y. J. Zhang, X. H. Zhang
File Type: Journal Paper
Issue:Volume: 29      Number: 11      Year: 2014
Download Link:Click here to download PDF     File Size: 570 KB

Title: Diamond Shaped Ring Antenna for UWB Applications with Inherent Band-Notched Functionality
Abstract: In this Letter, a novel printed monopole antenna design is described that operates across a wideband frequency band and exhibits band-notch characteristic necessary to suppress interference signals. The prototype antenna consists of a radiating patch in the configuration of a diamond shaped ring that has attached within it an inverted T-shaped resonant structure that controls the notch frequency. The antenna is excited with a microstrip feed-line and includes an elliptically shaped ground-plane that is defected with a dielectric notch in the vicinity of the patch to enhance the antenna’s impedance bandwidth. The antenna exhibits an inherent stopband function at the WLAN frequency band. The proposed antenna configuration is simple and compact with dimensions of 30×30×1.6 mm3 . The measured impedance bandwidth exceeds the UltraWideband (UWB) spectrum defined between 3.06- 15.96 GHz, for VSWR?2 that corresponds to a fractional bandwidth of 135.6%. The radiation characteristic of the proposed antenna is approximately omni-directional.
Author(s): M. Shokri, Z. Amiri, S. Asiaban, B. Virdee
File Type: Journal Paper
Issue:Volume: 29      Number: 11      Year: 2014
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Title: Electromagnetic Force Calculation of Conductor Plate Double Halbach Permanent Magnet Electrodynamic Suspension
Abstract: In order to solve the problem of high drag force in traditional Permanent Magnet Electrodynamic Suspension (PM-EDS) and increase the levitation-drag force ratio, this paper proposes a new suspension system composed of conductor plates and a double Halbach permanent magnet array, and calculates its electromagnetic force. The eddy current distribution equation for the conductor plate and the analytic calculation formula for the electromagnetic force of the device are derived by solving the differential equations for the magnetic vector potential in space. Verifying the analytic method using the finite element method, the maximum and mean relative errors of the results were calculated to be 4% and 1.7%, respectively. This paper also compares the levitation-drag force ratio of the new suspension system with that of the traditional system and concludes that the new system can substantially reduce the drag force and power loss.
Author(s): Y. Chen, K. Zhang
File Type: Journal Paper
Issue:Volume: 29      Number: 11      Year: 2014
Download Link:Click here to download PDF     File Size: 676 KB

Title: A Novel Fractal Monopole Antenna with Wide Bandwidth Enhancement for UWB Applications
Abstract: A novel wideband fractal monopole antenna with a semi-elliptical ground plane is presented. In this letter, by inserting a fractal shape in the conventional circular ring, much wider impedance bandwidth and new resonances are generated. By only increasing the fractal iterations, larger bandwidth is attained. The designed antenna has a compact size of 25×25×1 mm3 and operates over the frequency band between 2.2 and 17 GHz for VSWR<2. The process of improving the impedance bandwidth and measured results are presented and discussed.
Author(s): B. Heydari, Z. Sanaati, V. Waladi, Y. Zehforoosh
File Type: Journal Paper
Issue:Volume: 29      Number: 11      Year: 2014
Download Link:Click here to download PDF     File Size: 525 KB

Title: 60-GHz 3-D Cavity Bandpass Filter for V-Band Gigabit Wireless Systems
Abstract: In this paper, a compact 60-GHz Three-Dimensional (3-D) SIW-based bandpass filter is presented using Low-Tmperature Cofired Ceramic technology (LTCC). The filter is composed of four cavities. The coupling scheme is made up of three direct coupling and one cross coupling between the first and the fourth SIW cavities. By using the cross coupling technology and the cavity transformation property, two Transmission Zeros (TZs) are introduced outside the passband to increase the filtering selectivity. Both simulated and measured results are presented in good agreement.
Author(s): G. Zhang, J. Wang, H. Gu, X. Xu
File Type: Journal Paper
Issue:Volume: 29      Number: 11      Year: 2014
Download Link:Click here to download PDF     File Size: 732 KB