ACES Publication Search
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| Title: | ACES Journal June 2014 Cover |
| File Type: | Journal Paper |
| Issue: | Volume: 29 Number: 6 Year: 2014 |
| Download Link: | Click here to download PDF File Size: 28035 KB |
| Title: | ACES Journal June 2014 Front/Back Matter |
| File Type: | Journal Paper |
| Issue: | Volume: 29 Number: 6 Year: 2014 |
| Download Link: | Click here to download PDF File Size: 23 KB |
| Title: | ACES Journal June 2014 Full |
| File Type: | Journal Paper |
| Issue: | Volume: 29 Number: 6 Year: 2014 |
| Download Link: | Click here to download PDF File Size: 14346 KB |
| Title: | Lowpass Filter Design Based on Microstrip Meander Line with HDGS |
| Abstract: | A microstrip meander line with a single H-shaped Defected Ground Structure (HDGS) is employed to design a novel compact lowpass filter with sharp roll off and wide stop band. Two parametric studies were conducted to analyze the sensitivity of the HDGS position and the size effects on the filter response. The design is fabricated to have a 6 GHz cutoff frequency using Rogers TMM 10i substrate, with an area of 7.6 x 6 mm2 . The measured results are in a good agreement with simulation prediction. |
| Author(s): | A. S. Al-Zayed, M. B. Asad Allah, S. F. Mahmoud |
| File Type: | Journal Paper |
| Issue: | Volume: 29 Number: 6 Year: 2014 |
| Download Link: | Click here to download PDF File Size: 1152 KB |
| Title: | Finite-Difference Time-Domain Modeling of Ultra-High Frequency Antennas on and Inside the Carbon Fiber Body of a Solar-Powered Electric Vehicle |
| Abstract: | Finite-difference time-domain simulations are performed on a 900 MHz band antenna inside and outside the carbon fiber body of a solar-powered electric vehicle. Data is analyzed to determine the optimal antenna placement for transmission to a receiving antenna located toward the rear of the solar vehicle. Modeling data is compared to experimental results. Computational fluid dynamics are used to determine acceptability of external antenna placement. It is found that the ideal antenna would be inside the vehicle’s body and oriented vertically, but that the portion of the body surrounding the antenna must be constructed of a non-conductive material. |
| Author(s): | K. Han, P. Freeman, H.-Y. Han, J. Hamar, J. F. Stack Jr. |
| File Type: | Journal Paper |
| Issue: | Volume: 29 Number: 6 Year: 2014 |
| Download Link: | Click here to download PDF File Size: 4310 KB |
| Title: | Ultra-Wideband Antenna with Variable Notch Band Function by Defected Ground Structure and Shorting Pin |
| Abstract: | In this paper, a simple miniaturized printed antenna for ultra-wideband applications with variable band-notch function is proposed. The presented antenna consists of a square radiating patch and a ground plane with inverted T-shaped slot, which increases the bandwidth of 2.3-11 GHz. Frequency band-stop performance is created by two techniques: Defected Ground Structure (DGS) and shorting pins. The designed antenna has a small size of 17×21×1 mm3 , while showing the band rejection performance in the frequency bands of 3.2 to 3.8 and 5.1 to 5.85 GHz, respectively. |
| Author(s): | M. Akbari, R. Movahedinia, A. Sebak |
| File Type: | Journal Paper |
| Issue: | Volume: 29 Number: 6 Year: 2014 |
| Download Link: | Click here to download PDF File Size: 1177 KB |
| Title: | Applications of ANN and ANFIS to Predict the Resonant Frequency of L-Shaped Compact Microstrip Antennas |
| Abstract: | Since the Compact Microstrip Antennas (CMAs) with various shapes are crucial for mobile communication, they take much attention in present days and studies related to analysis and design on them have been increasing day by day. In this work, simple approaches based on Artificial Neural Network (ANN) and Adaptive Neuro-Fuzzy Inference System (ANFIS) for computing the resonant frequency of L-shaped CMAs operating at UHF band have been presented. In order to train and test the ANN and ANFIS models, 192 LCMAs having different physical dimensions and relative dielectric constants were simulated by electromagnetic simulation software named IE3D™, which is based on Method of Moment (MoM). 172 of LCMAs were employed for training, while the remainders were utilized for testing the models. Average Percentage Errors (APEs) for training were obtained as 0.345% and 0.090% for ANN and ANFIS models, respectively. The constructed models were then tested over the test data and APEs values were achieved as 0.537% for ANN and 0.454% for ANFIS. Afterwards, the accuracy and validity of ANN and ANFIS models proposed in this work were verified on measurement data of the fabricated LCMAs. The results indicate that ANN and ANFIS can be successfully used to predict the resonant frequency of LCMAs without necessitating any other sophisticated calculations. |
| Author(s): | A. Kayabasi, A. Toktas, A. Akdagli, M. B. Bicer, D. Ustun |
| File Type: | Journal Paper |
| Issue: | Volume: 29 Number: 6 Year: 2014 |
| Download Link: | Click here to download PDF File Size: 1216 KB |
| Title: | Impact of the Hand on the Specific Absorption Rate in the Head |
| Abstract: | In this article, we have investigated the influence of the hand on the Specific Absorption Rate (SAR) in the head for single and dualantenna mobile terminals. The SAR in the head has been evaluated via Finite Difference Time Domain (FDTD) numerical computations. In the numerical models, the user has been represented not only by using the Specific Anthropometric Mannequin (SAM) head phantom, but also by including a hand phantom. Two types of hand grips (soft and firm) have been used to investigate the impact of the hand on the SAR. Moreover, the influence of the index finger position on the SAR has been investigated by using hand models with different locations of the index finger. At low band, the SAR evaluation in the head without including the hand phantom overestimates the actual value, with the hand phantom presents independently on the type, location and number of antennas. The highest overestimation of 50% has been observed for the mobile terminal with bottom positioned Folded J Antenna (FJA). At the high band and when considering the dual-antenna mobile terminals, the hand increases the SAR in the head by up to 40% compared to the respective calculated values without a hand phantom. Further, the SAR evaluation when the firm hand grip is used can be considered as a worst case estimation, because higher SAR values in the head have been obtained compared to when using the soft phantom. |
| Author(s): | I. B. Bonev, O. Franek, G. F. Pedersen |
| File Type: | Journal Paper |
| Issue: | Volume: 29 Number: 6 Year: 2014 |
| Download Link: | Click here to download PDF File Size: 1798 KB |
| Title: | Focusing of Electromagnetic Wave from Quartic Inhomogeneous Chiro-Slab |
| Abstract: | The focusing of electromagnetic waves from a quartic inhomogeneous chiro-slab is examined, using Maslov’s method. Analytic field expressions are derived for the transmission coefficients at the interfaces and numerical computations are made to determine the field behavior around the caustic point of the chiro-slab. The effects of chirality parameter, permittivity and permeability on the intensity of the field around caustic point of the chiro-slab are also discussed. The results obtained through this method are shown to be in good agreement with those obtained from Huygens Kirchhoff’s integral. |
| Author(s): | A. Ghaffar, M. Sharif, Q. A. Naqvi, M. A. S. Alkanhal, F. Khalid, S. Shukurullah |
| File Type: | Journal Paper |
| Issue: | Volume: 29 Number: 6 Year: 2014 |
| Download Link: | Click here to download PDF File Size: 646 KB |
| Title: | Comparison and Analyzing of Propagation Models with Respect to Material, Environmental and Wave Properties |
| Abstract: | This paper presents a study on a class of algorithms based on Uniform Theory of Diffraction (UTD) for multiple diffractions. Within this context Slope UTD with Convex Hull (S-UTD-CH) model based on Slope UTD and Fresnel zone concept was reviewed. S-UTD-CH model can be used for fast and more accurate field prediction for multiple diffractions in transition zone. An extensive simulation results for comparison of UTD based algorithms with respect to the computation time and accuracy was provided. Furthermore, the study shows how relative permittivity constant, conductivity and inner angle of wedge and polarization type affect the relative path loss. |
| Author(s): | M. B. Tabakcioglu, D. Ayberkin, A. Cansiz |
| File Type: | Journal Paper |
| Issue: | Volume: 29 Number: 6 Year: 2014 |
| Download Link: | Click here to download PDF File Size: 424 KB |
| Title: | Low Profile Dual Band-Notched Slot Antenna with Modified Ground Plane for UWB Systems |
| Abstract: | In this paper, a new compact microstrip-fed slot antenna with dual band-notched performance for Ultra-Wideband (UWB) communications is presented. In the proposed structure, by using an inverted U-shaped conductor-backed plane, a new resonance at 12.5 GHz is excited and hence much wider impedance bandwidth can be produced. In order to generate a single band-notched function, we use an inverted T-shaped strip protruded inside the rectangular slot, with this structure first rejection band around of 3.3-4.2 GHz can be achieved. By inserting a pair of C-shaped slots in the ground plane, dual bandnotched function can be produced. The measured results reveal that the presented dual band-notched slot antenna offers a wide bandwidth from 2.62 GHz to 13.81 GHz, with two notched bands covering all the 5.2/5.8 GHz WLAN, 3.5/5.5 GHz WiMAX and 4-GHz C bands. The proposed antenna has a small size. Simulated and experimental results obtained for this antenna show that it exhibits good radiation behavior within the UWB frequency range. |
| Author(s): | N. Ojaroudi, N. Ghadimi, Y. Ojaroudi |
| File Type: | Journal Paper |
| Issue: | Volume: 29 Number: 6 Year: 2014 |
| Download Link: | Click here to download PDF File Size: 1293 KB |
| Title: | Optimization-Based Matching Layer Design for Broadband Dielectric Lens Antennas |
| Abstract: | Dielectric lens antennas fabricated with a dense dielectric material, allow good power transfer efficiency through the lens and enable fabrication of low-cost and compact-size lens antennas. On the contrary, using dense dielectric material causes strong multiple internal reflection behavior inside the lens antenna. These multiple reflections deteriorate not only return loss but also the radiation characteristics. However, the undesirable effects of strong internal reflections can be reduced considerably using one or more dielectric Matching Layers (MLs) coated at the top of the antenna. In this paper, a novel optimizationbased ML design procedure for dielectric lens antennas is proposed. In order to demonstrate effectiveness of the method, the optimization procedure is applied to two different dielectric lens antennas; a narrow band lens antenna and an Ultra-Wideband (UWB) lens antenna. The simulation results verify that MLs designed by the proposed optimization procedure prevent strong internal reflections successfully for both narrowband and UWB applications. |
| Author(s): | F. Tokan |
| File Type: | Journal Paper |
| Issue: | Volume: 29 Number: 6 Year: 2014 |
| Download Link: | Click here to download PDF File Size: 1251 KB |
| Title: | A Novel Compact Printed Slot Antenna with Triple Bands for WiMAX/WLAN Applications Using Remodeling Technology |
| Abstract: | A novel compact triple-band Printed Slot Antenna (PSA) fed by CPW is presented in this paper. By attaching a crescent-shaped strip to the extremity of the CPW fed-line of a conventional CPW-fed circle slot antenna, a lower resonant mode is excited. Then, with an annular strip located between the circle slot and the crescent-shaped strip, an additional resonant mode and better impedance matching is achieved. Besides, a rectangular shorting stub is loaded at the appropriate position of the annular strip to obtain more resonant modes. By adopting such remodeling technology, the aperture utilization efficiency is greatly improved, and thus, multifunctional integration in a compact size can be realized. The designed PSA, featuring of a small size of 23×30 mm, operates over the frequency ranges 2.33-2.7 GHz, 3.3-3.8 GHz and 4.83-6.26 GHz, with good omni-directional radiation patterns and rather stable antenna gains, is suitable for both WLAN and WiMAX applications. |
| Author(s): | L. Li, Z. Zhi-Li, L. Ming-Fu, J. Chang-Jiang, B. Tang |
| File Type: | Journal Paper |
| Issue: | Volume: 29 Number: 6 Year: 2014 |
| Download Link: | Click here to download PDF File Size: 1796 KB |