ACES Publication Search
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| Title: | ACES Journal February 2014 Front/Back Matter |
| File Type: | Journal Paper |
| Issue: | Volume: 29 Number: 2 Year: 2014 |
| Download Link: | Click here to download PDF File Size: 22 KB |
| Title: | ACES Journal February 2014 Full |
| File Type: | Journal Paper |
| Issue: | Volume: 29 Number: 2 Year: 2014 |
| Download Link: | Click here to download PDF File Size: 22866 KB |
| Title: | ACES Journal February 2014 Cover |
| File Type: | Journal Paper |
| Issue: | Volume: 29 Number: 2 Year: 2014 |
| Download Link: | Click here to download PDF File Size: 2654 KB |
| Title: | Time-Domain Integral Equation Solver Using Variable-Order Temporal Interpolators |
| Abstract: | A novel, efficient, and simple modification to standard marching-on-in-time (MOT)–based time-domain integral equation (TDIE) solvers is presented. It allows for the use of high-order temporal interpolators without the need to extrapolate and predict future unknowns. The order of these temporal interpolators is increased as the distance of source and testing quadrature points increases. The proposed TDIE solver significantly increases the accuracy of solutions by exploiting high-order temporal interpolation at no significant extra computational cost. Numerical examples are presented to validate the proposed method. |
| Author(s): | M. Ghaffari-Miab, F. Valdes, R. Faraji-Dana, E. Michielssen |
| File Type: | Journal Paper |
| Issue: | Volume: 29 Number: 2 Year: 2014 |
| Download Link: | Click here to download PDF File Size: 991 KB |
| Title: | Spherical Conformal Bow-Tie Antenna for Ultra-Wide Band Microwave Imaging of Breast Cancer Tumor |
| Abstract: | In this paper, contribution of spherical conformal ultra-wide band (UWB) bow-tie antenna on enhancement of breast tumor detection capability of a radar-based microwave imaging system is investigated through simulation, demonstrating the potential of the novel antenna element used in a half-spherical antenna array surrounding the breast. The designed conformal antenna operates efficiently across the band from 1 GHz to 8 GHz, and it is immersed in a coupling medium in order to get a good impedance matching with the breast. Images are successfully formed by using delay-and-sum (DAS) algorithm for the detection of a spherical tumor model with 2 mm diameter. The tumor is located at 40 mm depth inside three different breast phantom models with homogeneous fatty breast tissue, quasiheterogeneous mix of fibro-glandular and fatty breast tissues and homogeneous fibro-glandular tissue, respectively. Fidelity factor, indicating the maximum cross correlation between observed and excitation pulses, of the conformal bow-tie is found to be around 13% more than that of the planar bow-tie at 40 mm depth. The use of the spherical conformal antenna presents an excellent solution to increase tumor responses by at least 2.3 dB, as well as to decrease mutual coupling effects between array elements, compared to the same system with planar bow-tie antennas |
| Author(s): | I. Unal, B. Turetken, C. Canbay |
| File Type: | Journal Paper |
| Issue: | Volume: 29 Number: 2 Year: 2014 |
| Download Link: | Click here to download PDF File Size: 3108 KB |
| Title: | A CPW-Fed Band-Notched UWB Antenna with T-shape Construct and Matching Branches |
| Abstract: | A compact coplanar waveguide (CPW) fed ultra-wideband (UWB) antenna with a bandnotched performance is presented in this paper. The band-notched UWB antenna is designed on a 26×34×1.6 mm3 substrate. It consists of a circle ring with a T-shape construct, three rectangular matching branches, a rectangular transition branch, and a CPW feed line. The antenna is simulated and the geometrical parameters of the antenna selected with Ansoft HFSS. The simulated results show the impedance bandwidth covers from 3.0 GHz to 11.0 GHz with the notched rejection band of 5.1 GHz - 5.8 GHz. A prototype was fabricated and tested. The measured and simulated results show that the proposed antenna gives bidirectional radiation pattern in the E-plane and omnidirectional radiation pattern in the Hplane with relatively flat gains in the pass-band. Due to its compact configuration, the antenna can find good UWB applications. |
| Author(s): | A. Chen, C. Yang, Z. Chen, K. AN, J. Fang, W. Jiang |
| File Type: | Journal Paper |
| Issue: | Volume: 29 Number: 2 Year: 2014 |
| Download Link: | Click here to download PDF File Size: 4845 KB |
| Title: | Modal Analysis for a Waveguide of Nanorods Using the Field Computation for a Chain of Finite Length |
| Abstract: | The propagation of light along an infinite 2D chain of silver nanorods is analyzed and the dispersion for this waveguide is computed using field computation for a finite chain of nanorods. In this work, generalized multipole technique is used for the analysis. This method calculates the imaginary and real parts of the propagation constant by exciting the chain in one end and observing propagation of modes along the chain far enough from the excitation. It is shown that a short chain of finite length is sufficient for the calculation of the phase constant while the attenuation constant requires a longer chain. Field distribution is depicted for even and odd modes and it is shown that in the simulated frequency range only two modes can be excited and can propagate along the waveguide. |
| Author(s): | Y. Rahbarihagh, F. Kalhor, J. Rashed-Mohassel, M. Shahabadi |
| File Type: | Journal Paper |
| Issue: | Volume: 29 Number: 2 Year: 2014 |
| Download Link: | Click here to download PDF File Size: 2114 KB |
| Title: | Single Feed Dual-Polarization Dual-Band Transmitarray for Satellite Applications |
| Abstract: | In this paper, two transmitarrays are designed, analyzed, and simulated for satellite applications. The first transmitarray is designed for dual linear polarization at a center frequency of 12 GHz. The second transmitarray is designed for two frequency bands: 17.15 GHz to 17.9 GHz for vertical polarization and 11.5 GHz to 12.4 GHz for horizontal polarization. The dual polarization is obtained by an independent adjustment of the dimensions of two orthogonal slots in the transmitarray unit cell. The design is carried out independently for each polarization. The transmitarray unit cell uses two dielectric substrate layers arranged to be one on each side of a conducting plane. On each substrate, one face has metallization containing the patches, and the other face has metallization containing the ground plane. The two patches are coupled by two cross slots of lengths LV and LH in the ground plane and each patch is loaded with two cross slots of lengths LV/2 and LH/2. The unit cell achieves 360o of phase agility with less than 3.8 dB of variation in the transmission magnitude in the tuning range. The transmitarray consisted of 17×17 elements with the unit cell size were set at 13 mm. A circular feed horn is located on the central normal to the transmitarray and the configuration looks like a lens antenna. Two separate feeding pins are used to excite the horn antenna for horizontal and vertical polarizations. The results are worked out using two basically different numerical techniques, the finite element method, FEM, and the finite integration technique, FIT. Good agreement was obtained. |
| Author(s): | S. Zainud-Deen, S. Gaber, H. Malhat, K. Awadalla |
| File Type: | Journal Paper |
| Issue: | Volume: 29 Number: 2 Year: 2014 |
| Download Link: | Click here to download PDF File Size: 353 KB |
| Title: | Broad-Band Power Divider Based on the Novel Split Ring Resonators |
| Abstract: | A broad-band power divider, based on proposed novel split ring resonators, with the use of surface-mount components, is presented in this paper. This paper is focused on the design of generalized novel split ring resonators in a fully planar configuration. This novel split ring resonator exhibits multiple, alternating backward and forward-transmission bands, and is therefore promising for the synthesis of wideband microwave components. The equivalent circuit models, including parasitic parameters, of the structures is presented (based on electrically small planar resonators), the detailed procedure for the synthesis of these resonators by using the proposed circuit model, is illustrated. It is shown that excellent results in both performance and size can be obtained through the proposed approach, fully compatible with planar technology. |
| Author(s): | D. Jiang, Y. Xu, R. Xu, Z. Shao |
| File Type: | Journal Paper |
| Issue: | Volume: 29 Number: 2 Year: 2014 |
| Download Link: | Click here to download PDF File Size: 1261 KB |
| Title: | An Efficient 2D Rough Surface Scattering Analysis Using Strong Harmonics Extraction and the Kirchhoff Approach |
| Abstract: | An efficient method for scattering analysis from slightly rough surfaces is introduced. This method can be used in ray tracing algorithm where the computational efficiency is important due to the complexity and size of problems. In this method, the Kirchhoff approach is used for a periodic extension of the finite surface, which is approximated by strong harmonics of its Fourier series. Typical asphalt surfaces are analyzed by this method in millimeter-wave band and validated with the method of moments. The dominant scattering angles and ray widths of the scattered field can be easily used in ray tracing algorithm. The computation time and accuracy of results show that this method can be used for rough surface scattering analysis in ray tracing algorithm efficiently. |
| Author(s): | A. Torabi, A. A. Shishegar |
| File Type: | Journal Paper |
| Issue: | Volume: 29 Number: 2 Year: 2014 |
| Download Link: | Click here to download PDF File Size: 1486 KB |
| Title: | A Compact UWB Band-Pass Filter with Ultra-Narrow Tri-Notch-Band Characteristic |
| Abstract: | This paper proposes a novel approach for designing compact ultra-wideband (UWB) band-pass filter with a good tri-notch-band characteristic, which is obtained by using the ringstub multimode resonator (MMR). The equivalent model of the filter is achieved by using odd/even excitation resonance condition. The characteristics of the designed filter are investigated and analyzed by means of IE3D. This filter is designed, analyzed, fabricated, and measured successfully. Experimental and numerical results show that the proposed filter, with compact size of 25×10 mm2 , has an impedance bandwidth range from 3 GHz to 10.6 GHz with the triple notch bands at 4.14 GHz, 6.1 GHz, and 7.1 GHz. The proposed filter can be incorporated into UWB radio systems in order to efficiently enhance the interference immunity from undesired signals. |
| Author(s): | Y. Li, W. Li, C. Liu, Qiubo Ye |
| File Type: | Journal Paper |
| Issue: | Volume: 29 Number: 2 Year: 2014 |
| Download Link: | Click here to download PDF File Size: 3333 KB |
| Title: | Microstrip Patch Antenna Covered With Left Handed Metamaterial |
| Abstract: | We present gain characteristics of microstrip patch antennas covered with metamaterial substrate composed of split-ring resonators (SRRs) and metallic strip. To determine the performance of the SRR-metallic strip mounted on microstrip patch antenna, the metamaterial has been proposed as an effective medium with extracted constitutive parameters. Simulation results are supported by experimental measurements. The experimental results confirm that the metamaterial covered patch antenna improves gain by an amount of -5.68 dB (60.3%) as well as radiation pattern (-8 dB to +20 dB) at WLAN communication. |
| Author(s): | E. Dogan, E. Unal, D. Kapusuz, M. Karaaslan, C. Sabah |
| File Type: | Journal Paper |
| Issue: | Volume: 29 Number: 2 Year: 2014 |
| Download Link: | Click here to download PDF File Size: 2161 KB |
| Title: | Application of the Protruded Structures to Design an UWB Slot Antenna with Band-Notched Characteristic |
| Abstract: | A different method to design a novel ultra-wideband (UWB) slot antenna with bandnotch performance is presented. In order to increase the impedance bandwidth of the slot antenna, we use a rectangular slot with a pair of Lshaped strips protruded inside the rectangular slot in the ground plane that with this structure UWB frequency range can be achieved. Additionally, by using square-ring radiating stub with two -shaped strips protruded inside the square-ring stub, a frequency notch band performance has been obtained. The designed antenna has a small size of 20×20 mm2 while showing the radiation performance in the frequency band of 3.07 GHz to over 14.67 GHz with a band rejection performance in the frequency band of 5.05 GHz to 5.93 GHz. Simulated and experimental results obtained for this antenna show that it exhibits good radiation behavior within the UWB frequency range. |
| Author(s): | N. Ojaroudi, M. Mehranpour, S. Ojaroudi, Y. Ojaroudi |
| File Type: | Journal Paper |
| Issue: | Volume: 29 Number: 2 Year: 2014 |
| Download Link: | Click here to download PDF File Size: 4075 KB |