ACES Publication Search
There are 18 search results for:
| Title: | ACES Journal December 2016 Cover |
| File Type: | Journal Paper |
| Issue: | Volume: 31 Number: 12 Year: 2016 |
| Download Link: | Click here to download PDF File Size: 2122 KB |
| Title: | ACES Journal December 2016 Front/Back Matter |
| File Type: | Journal Paper |
| Issue: | Volume: 31 Number: 12 Year: 2016 |
| Download Link: | Click here to download PDF File Size: 207 KB |
| Title: | ACES Journal December 2016 Full |
| File Type: | Journal Paper |
| Issue: | Volume: 31 Number: 12 Year: 2016 |
| Download Link: | Click here to download PDF File Size: 13639 KB |
| Title: | Reconstruction of the Antenna Far-Field Pattern through a Fast Plane-Polar Scanning |
| Abstract: | This paper provides the experimental validation of a fast and accurate technique, which allows the reconstruction of the antenna radiation pattern from a minimum number of near-field measurements collected through a plane-polar scanning. This near-field to far-field (NFTFF) transformation technique relies on a nonredundant sampling representation of the voltage acquired by the probe, achieved by modeling the antenna with a double bowl, a very flexible model particularly suitable to deal with antennas having a quasi-planar geometry. The NF data required by the standard plane-rectangular NFTFF transformation are efficiently reconstructed from the nonredundant plane-polar ones by using an optimal sampling interpolation algorithm, thus making possible to get a considerable measurement time saving. The accuracy and practical efficacy of the described technique are assessed by experimental tests carried out at the Antenna Characterization Lab of the University of Salerno. |
| Author(s): | F. D'Agostino, F. Ferrara, C. Gennarelli, R. Guerriero, M. Migliozzi |
| File Type: | Journal Paper |
| Issue: | Volume: 31 Number: 12 Year: 2016 |
| Download Link: | Click here to download PDF File Size: 1998 KB |
| Title: | The Fourth-Order One-Step Leapfrog HIE-FDTD Method |
| Abstract: | A new fourth-order one-step leapfrog hybrid implicit-explicit finite-difference time-domain (HIEFDTD) method has been proposed in this paper. This new method investigates the use of a second-order accurate in time and a fourth-order accurate in space. Because of the utilize of the one-step leapfrog theory, the proposed algorithm not only has the same formulation as that used for the traditional FDTD, but also require only one-step computations. The 2-D formulation of the method is presented and the time stability condition of the method is certified. Simulation results show that the proposed method is 6.8 times faster than the traditional second-order FDTD method and is 2.2 times faster than the second-order HIE-FDTD method, which shows that the proposed method has very high computational efficiency. On the other hand, the proposed method also has less dispersion error by comparing with traditional second-order FDTD method and the second-order HIEFDTD method. |
| Author(s): | M. Dong, A. Zhang, J. Chen, S. Zhang, Y. He |
| File Type: | Journal Paper |
| Issue: | Volume: 31 Number: 12 Year: 2016 |
| Download Link: | Click here to download PDF File Size: 1628 KB |
| Title: | A Speeding up Technique for Lossy Anisotropic Algorithm in FDTD Method |
| Abstract: | In this paper, a speeding up technique for the lossy anisotropic (Lossy-ANI) algorithm integrated into the finite-difference time-domain (FDTD) method is proposed. The speeding up technique provides remarkable reduction in the computation time of the Lossy-ANI algorithm. This algorithm is applied to a line-fed microstrip patch antenna (MPA) with anisotropic substrate and a lossy anisotropic scattering object. Numerical results show that the anisotropy effects the resonant frequencies of the MPA and the bistatic RCS of the scattering object. |
| Author(s): | F. Kaburcuk, A. Z. Elsherbeni |
| File Type: | Journal Paper |
| Issue: | Volume: 31 Number: 12 Year: 2016 |
| Download Link: | Click here to download PDF File Size: 2055 KB |
| Title: | Full-Wave Analysis of Microstrip Circuits with Reciprocal Matrix Compression Technique |
| Abstract: | We propose an efficient full-wave simulation method for microstrip circuits with reciprocal multilevel matrix compression method (rMLMCM). The mixed potential integral equation (MPIE) with the layered media Green’s function is applied to the exterior layers of the packed interconnects. With quadtree structure, the dense impedance matrix is split up into the “near” and “far” terms according to the admission condition. The “near” term block matrices are full-rank, they are evaluated by the method of moments (MoM) directly. While the “far” term block matrices are low-rank, they are sparse filled and compressed by the rMLMCM. The rMLMCM low-rank approximation precisions of the block impedance matrices with respect to the decomposition thresholds are tested in detail. The current densities on the large-scale interconnects at high frequency are extracted much more effectively with the rMLMCM over the standard rank based methods. Numerical results demonstrate the validity of the proposed method. |
| Author(s): | M. Li, C. Xia, R. Chen |
| File Type: | Journal Paper |
| Issue: | Volume: 31 Number: 12 Year: 2016 |
| Download Link: | Click here to download PDF File Size: 1866 KB |
| Title: | Finite Element Analysis of Three Dimensional Complex Scatterers in Layered Media |
| Abstract: | In this paper, an efficient three-dimensional finite-element method (FEM) is introduced to study the scattering from complex three-dimensional objects in the layered media. The proposed method is valid to targets which are located either close to or far away from the media interface. Furthermore, the interface can be either a planar or rough surface in the computational domain. To improve efficiency, the preconditioned conjugate gradient method for normal equations (CGN) are proposed to solve the FEM linear system. Numerical examples are presented to demonstrate the accuracy and efficiency of the presented method. |
| Author(s): | X. Ping, X. Yin, L. Li, C. Li, Q. Li |
| File Type: | Journal Paper |
| Issue: | Volume: 31 Number: 12 Year: 2016 |
| Download Link: | Click here to download PDF File Size: 2818 KB |
| Title: | A New HIE-PSTD Method for Solving Problems with Fine and Electrically Large Structures Simultaneously |
| Abstract: | A new hybrid implicit-explicit difference and pseudospectral (PS) scheme is presented for solving the electromagnetic problems which have fine features and are electrically large. The maximum time-step size in this method is only determined by two spatial discretization which only need two cells per wavelength. The formulation of the method is presented and the time stability condition of the method is demonstrated. This method is more efficient than the finite-difference timedomain (FDTD) method in terms of computer memory and computation time, which is demonstrated through numerical examples. |
| Author(s): | J. Guo, J. Chen, J. Wang, A. Zhang |
| File Type: | Journal Paper |
| Issue: | Volume: 31 Number: 12 Year: 2016 |
| Download Link: | Click here to download PDF File Size: 1661 KB |
| Title: | Development of a Low Profile and Wideband Backward-Wave Directional Coupler Using Neural Network |
| Abstract: | In this paper, a low profile and wideband backward-wave directional coupler is introduced. It operates similar to the composite right left handed (CRLH) couplers. Two different mechanisms including connections between the coupled lines to provide shunt inductance for odd mode and defected ground structure (DGS) to add series capacitance for even mode are applied to obtain high performance and wideband coupler. Neural network process is used to obtain the optimized parameters of the proposed coupler. The introduced coupler is then numerically investigated using full wave simulator software. A prototype of the proposed coupler is fabricated and successfully tested. The measured results are in a good agreement with those obtained by simulation. The measured coupling level is 0.49 dB over the frequency range from 6.5 GHz up to 14 GHz, which shows fractional bandwidth of 73.2%. |
| Author(s): | Z. S. Tabatabaeian, M. H. Neshati |
| File Type: | Journal Paper |
| Issue: | Volume: 31 Number: 12 Year: 2016 |
| Download Link: | Click here to download PDF File Size: 1953 KB |
| Title: | Planar Dual-Band WLAN MIMO Antenna with High Isolation |
| Abstract: | In this paper, a dual-band multiple-input multiple-output (MIMO) antenna with a planar and rotational symmetric structure is presented. The proposed antenna comprises two via-fed monopole antennas arranged orthogonally in cross-pairs. When each monopole is excited, the other can be employed as a parasitic element. By properly adjusting the antenna dimensions, two resonant modes can be generated at about 2.45 and 5.6 GHz. Besides, the radiation patterns of two monopoles are orthogonal to each other, resulting in good pattern diversity and high isolation without using additional decoupling methods. Measured results show that two operating bands ranging from 2.3-2.75 and 5.09-6.16 GHz are obtained, which can cover the whole (2.4/5.2/5.8-GHz) wireless local area network (WLAN) bands. Port-to-port isolation is more than 24 and 22 dB at the lower and higher operating bands, respectively. Envelope correlation coefficient is studied as well. |
| Author(s): | H. Li, L. Kang, Y. Xu, Y.-Z. Yin |
| File Type: | Journal Paper |
| Issue: | Volume: 31 Number: 12 Year: 2016 |
| Download Link: | Click here to download PDF File Size: 1923 KB |
| Title: | A Compact Planar Ultra Wideband Antenna with Triple-Notched Bands Using Capacitive Coupled and Parallel LC Elements |
| Abstract: | Overlapping of frequency bands such as Worldwide Interoperability for Microwave Access (WiMAX), Wireless Local Area Network (WLAN) and International Telecommunication Union (ITU) bands with Ultra Wide Band (UWB) cause serious interference problems. As an attempt to reduce the effect of this coexistence, a triple band-notched monopole antenna is presented. A modified semi ellipse element with two I-shaped slots is used as the ground plane. A U-shaped slot, a pair of inverted L-shaped strips, and a modified G-slot structure which act as parallel LC circuit and capacitive-coupled elements, are embedded in feed line and radiation patch to create the triple band notch characteristics. The notched bands position can be controlled by tuning the dimensions of the foregoing filtering elements. The proposed antenna has been fabricated and measured. According to the measured results, the antenna operates over the frequency band of 2.5-16.5 GHz with three notched bands at the 5-6.2 GHz (WLAN), 3.1-4 GHz (WiMAX), and 7.15-8.1 GHz (X-band). |
| Author(s): | A. Araghi |
| File Type: | Journal Paper |
| Issue: | Volume: 31 Number: 12 Year: 2016 |
| Download Link: | Click here to download PDF File Size: 2133 KB |
| Title: | A Four-Leaf Clover Shape MIMO Antenna for UWB Applications |
| Abstract: | This paper proposes a quad-element multipleinput multiple-output (MIMO) antenna for handheld wireless Ultra-wideband (UWB) devices, which has pocket dimensions of 40 mm × 40 mm. An elaborate tapered slot antenna fed by a gradient microstrip acts as the single radiation element. The slots evolved from exponential function are to achieve the UWB properties, and the four slots which aim to four directions constitute the four-leaf clover shape. The UWB antenna shows good impedance (S11 < -10 dB) match in a UWB band from 4 GHz to 13 GHz and performs high efficiency (above 80%) and high isolation (S21, S31 < -20 dB). Realized gain is around 3 ~ 5 dB. The envelope correlation coefficient (ECC) is also investigated and it is within acceptance limits. |
| Author(s): | W. Yao, H. Yang, X. Huang, Z. Yu |
| File Type: | Journal Paper |
| Issue: | Volume: 31 Number: 12 Year: 2016 |
| Download Link: | Click here to download PDF File Size: 1804 KB |
| Title: | Transparent Flexible Antenna for UWB Applications |
| Abstract: | In this paper, a flexible circular slot transparent antenna which can be used in ultra wideband applications is presented. A CPW-fed circular disc monopole is used to excite the circular slot aperture. The antenna is designed and fabricated using ITO coated on a flexible Polyethylene Terephthalate (PET) substrate. It can operate with different curvature angles at UWB frequencies with 125% bandwidth. Simulation and measurement results show that the radiation pattern does not change if the antenna is being rolled, and also confirm its effective performance as a flexible transparent antenna with low profile. |
| Author(s): | M. R. Haraty, M. Naser-Moghadasi, A. A. Lotfi-Neyestanak, A. Nikfarjam |
| File Type: | Journal Paper |
| Issue: | Volume: 31 Number: 12 Year: 2016 |
| Download Link: | Click here to download PDF File Size: 1773 KB |
| Title: | Design of a Planar Surface Wave Antenna with a Bidirectional Pattern Based on Periodic Structures for Telemetry Applications |
| Abstract: | A planar surface wave antenna (PSWA) that realizes a bidirectional radiation pattern with a low profile configuration is designed, fabricated and measured. The antenna consists of a planar dielectric slab loaded with periodic spiral patches and EBG structure, which are designed to support the propagation of the surface waves in the desired direction. The diffraction of surface waves at the edges of the ground plane generates a bidirectional radiation pattern. The radiation mechanism and performance of the PSWA are described and simulated with commercial CST software. The proposed antenna with only 1.6 mm thickness is fabricated and tested, which resonates at 2.4 GHz. The antenna is especially attractive for telemetry applications because of its low profile and weight. |
| Author(s): | I. Mazraeh-Fard, M. Maddahali, Z. H. Firouzeh, H. K. Nekoei |
| File Type: | Journal Paper |
| Issue: | Volume: 31 Number: 12 Year: 2016 |
| Download Link: | Click here to download PDF File Size: 2219 KB |
| Title: | A Novel Tunable Graphene Based Terahertz Absorber with Polarization Insensitive |
| Abstract: | A novel design of the four-band graphene based terahertz (THz) absorber is presented. The pattern is formed by a graphene ring and orthogonal elliptical sheets on the top of a ground plate separated by a dielectric layer. Numerical results reveal that the graphene based absorber has four absorption peaks whose peaks are all over 99%. Besides, the absorption coefficient of the proposed absorber is insensitive to the polarization of the incident wave. And also, variation of geometrical parameter gives considerable freedom to change the resonance frequencies of the absorber. Moreover, the results reveal that the absorption spectra can be extended by tuning the chemical voltage of the graphene layer. |
| Author(s): | Sv. Masuminia , Ch. Ghobadi, J. Nourinia, M. Karamirad, B. Mohammadi |
| File Type: | Journal Paper |
| Issue: | Volume: 31 Number: 12 Year: 2016 |
| Download Link: | Click here to download PDF File Size: 2186 KB |
| Title: | Multiband and Perfect Absorber with Circular Fishnet Metamaterial and its Variations |
| Abstract: | In this study, a composite metamaterial unit cell is introduced based on experimentally proven circular fishnet metamaterials (CF-MMs) and its stripped versions to implement an absorber for Ku band microwave regime. The offered MM absorber shows the perfect absorptivity (99.9%), the near perfect absorptivity (96.2%) and the standard absorptivity (58%) over narrow band frequencies 14.28, 14.77 and 15.2 GHz, respectively. We offered a method to create a composite metamaterial unit cell consisting of resonant type metamaterial sub-unit cells that are not suitable for absorber implementations in normal conditions. The physical mechanism behind multi-band resonances in the left-handed medium (LHM) regime is explained in detail by revealing the reverse behavior in the right-handed medium (RHM) regime keeping a single resonance feature, based on cancellation of impinging electric fields and preservation of circulating electric fields around the MM space. A detailed analysis is performed to explore and compare the power losses due to imperfect dielectric and non-ideal conductor. |
| Author(s): | Y. Ozturk, A. E. Yilmaz |
| File Type: | Journal Paper |
| Issue: | Volume: 31 Number: 12 Year: 2016 |
| Download Link: | Click here to download PDF File Size: 2037 KB |
| Title: | Novel Mathematical Formulation of the Antenna Array Factor for Side Lobe Level Reduction |
| Abstract: | In this article a new approach is used to improve the performance of antenna arrays. The antenna array performance is improved when its directivity is increased and its side lobes are decreased. To do this, a concept of array hybridization (mixing two distinct arrays) is presented and applied to uniform arrays to generate a new array for satisfying the requirement. Two new arrays are generated using the proposed principle. The first is obtained from two arrays with different number of elements (UUDNH). The second generated array is based on the use of two arrays with different spacing between their elements (UUDdH). The obtained arrays parameters (array factor, side lobe levels, directivity and excitation coefficients) are given in closed form expressions. Furthermore, performances of the proposed arrays exceed that of Tschebyscheff arrays with the same number of elements. |
| Author(s): | O. Gassab, A. Azrar |
| File Type: | Journal Paper |
| Issue: | Volume: 31 Number: 12 Year: 2016 |
| Download Link: | Click here to download PDF File Size: 2382 KB |