ACES Publication Search
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| Title: | ACES April 2012 Full Journal |
| File Type: | Journal Paper |
| Issue: | Volume: 27 Number: 4 Year: 2012 |
| Download Link: | Click here to download PDF File Size: 6160 KB |
| Title: | ACES April 2012 Front/Back Matter |
| File Type: | Journal Paper |
| Issue: | Volume: 27 Number: 4 Year: 2012 |
| Download Link: | Click here to download PDF File Size: 607 KB |
| Title: | Breast Cancer Detection Using Support Vector Machine Technique Applied on Extracted Electromagnetic Waves |
| Abstract: | Breast cancer is one of the most common kinds of cancer, as well as the leading cause of decease among women. Early detection and diagnosis of breast cancer increases the chances for successful treatment and complete recovery for the patient. Mammography is currently the most sensitive method to detect early breast cancer; however, the magnetic resonance imaging (MRI) is the most attractive alternative to mammogram. Manual readings of mammograms may result in misdiagnosis due to human errors caused by visual fatigue. Computer aided detection systems (CAD) serve as a second opinion for radiologists. A new CAD system for the detection of breast cancer in mammograms is proposed. The discrete wavelet transform (DWT), the contourlet transform, and the principal component analysis (PCA) are all used for feature extraction; while the support vector machine (SVM) is used for classification.The system classifies normal and abnormal tissues in addition to benign and malignant tumors. A further investigation was implemented using electromagnetic waves instead of the classical MRI approach. A breast model was generated and near field data of electromagnetic waves were extracted to detect the abnormalities in the breast, especially the masses. |
| Author(s): | M. Al Sharkawy, M. Sharkas, D. Ragab |
| File Type: | Journal Paper |
| Issue: | Volume: 27 Number: 4 Year: 2012 |
| Download Link: | Click here to download PDF File Size: 882 KB |
| Title: | A Dynamic Measurement Method for Determining the Output Impedance of an RF Power Amplifier |
| Abstract: | Described herein is a novel approach for measuring the output impedance of a radio frequency (RF) power amplifier under actual operating (dynamic) conditions. The procedure involves loading the amplifier with three different values of resistance which are close to the intended load resistance value. Three separate experiments yield load excitation voltages (or powers) which permit direct calculation of the source complex impedance. The precision of determining the source impedance of the amplifier under test is only limited by the known tolerance of load resistance values used and the accuracy of measurements taken. The most important attribute of the technique described is that no requirement exists to alter the operating frequency. Also, the technique is applicable at microwave frequencies. |
| Author(s): | V. P. McGinn, V. Demir |
| File Type: | Journal Paper |
| Issue: | Volume: 27 Number: 4 Year: 2012 |
| Download Link: | Click here to download PDF File Size: 718 KB |
| Title: | Optimization of Reception Antenna Composed with Unbalanced Fed Inverted L Element for Digital Terrestrial Television |
| Abstract: | The structure of the array antenna for the reception antenna of the digital terrestrial television broadcasting in Japan is optimized by PSO algorithm. The unbalanced fed ultra low profile inverted L antenna is used as the driven element and two wires are located at the forward and backward directions of the driven element. In the case of antenna size of 170 mm by 325 mm by 29 mm, the return loss bandwidth less than -10 dB is satisfied at the whole broadcasting frequency band (240 MHz) and the directivity of 5.44 dBi to 7.19 dBi is obtained. In the numerical analysis, the electromagnetic simulator WIPL-D based on the method of moment is used. |
| Author(s): | D. Yagyu, M. Taguchi |
| File Type: | Journal Paper |
| Issue: | Volume: 27 Number: 4 Year: 2012 |
| Download Link: | Click here to download PDF File Size: 869 KB |
| Title: | Optimum Design of SIW Longitudinal Slot Array Antennas with Specified Radiation Patterns |
| Abstract: | In this paper, an optimum design is presented for substrate integrated waveguide (SIW) longitudinal slot array antennas based on the method of least squares (MLS). Elliott’s design procedure for dielectric filled waveguides is considered, taking into account the internal and external mutual couplings. The MLS error function is a multi-term function based on design goals, including specified radiation patterns and matching of the input impedance. We use the hybrid method of genetic algorithm-conjugate gradient for the error function minimization. This approach is very effective because of combining the “pattern synthesis” with “impedance matching” and “calculation of array parameters”. This procedure increases the speed of design as well as synthesizing patterns with specified characteristics. The MLS design results and those obtained by HFSS and CST simulation software are in good agreement and verify the accuracy of the proposed method. |
| Author(s): | S. E. Hosseininejad, N. Komjani, H. Oraizim, M. T. Noghani |
| File Type: | Journal Paper |
| Issue: | Volume: 27 Number: 4 Year: 2012 |
| Download Link: | Click here to download PDF File Size: 778 KB |
| Title: | Application of ANNs in Evaluation of Microwave Pyramidal Absorber Performance |
| Abstract: | To evaluate the overall anechoic chamber performance it is necessary to determine reflectivity of the absorbers. As manufacturer specifications usually give only information about frequency dependent reflection coefficient at normal incidence of EM waves, a time-consuming electromagnetic analysis is necessary to calculate the reflection coefficient at off-normal incident angles. In this paper, an efficient alternative approach to obtain the reflection coefficient at offnormal incidence is proposed. It is based on artificial neural networks trained to model the absorber reflectivity dependence on the frequency and incident angle of horizontally and vertically polarized electromagnetic waves. The model has been developed for pyramidal absorbers at low microwave frequencies (0.4 GHz–1 GHz). |
| Author(s): | M. Agatonovic, Z. Marinkovic, V. Markovic |
| File Type: | Journal Paper |
| Issue: | Volume: 27 Number: 4 Year: 2012 |
| Download Link: | Click here to download PDF File Size: 1033 KB |
| Title: | Design of High Performance Dual Frequency Concentric Split Ring Square Element for Broadband Reflectarray Antenna |
| Abstract: | An analysis of phase variation and phase range of concentric split ring square element for broadband reflectarray antenna is presented in this paper. This element is the combination of a splitted single square and ring element whereas the square element is the modification of the conventional annular ring in which, instead of using annul as the hole, this new idea presents a square as the hole in the ring. This will modifies the current distribution in the element which will then improve the performance of the bandwidth as the objective of this work. The physical interpretation of the elements is presented and variety of frequency responses pattern is described and analysed. The design procedure and critical parameters consist of phase range and phase slope (or variation) are also discussed. The proposed antenna element effectively covers two frequency operations (13.44 GHz and 18.36 GHz) in Kuband range. Bandwidth broadening is achieved by introducing the ring square combination of element and the practical phase range is achieved through the use of RF35 (thickness = 1.524 mm) as the substrate. The new concept of split initiates to a wider bandwidth (up to 67.6%) for the antenna and can applied to any two frequency operations of Ku-band applications. |
| Author(s): | S. H. Yusop, N. Misran, M. T. Islam, M. Y. Ismail |
| File Type: | Journal Paper |
| Issue: | Volume: 27 Number: 4 Year: 2012 |
| Download Link: | Click here to download PDF File Size: 1105 KB |
| Title: | A Switchable UWB Slot Antenna using SIS-HSIR and SIS-SIR for Multi-Mode Wireless Communications Applications |
| Abstract: | A coplanar waveguide (CPW) fed ultra wideband (UWB) antenna with switchable functions and notched band characteristics for multi-mode wireless communication applications is proposed in this paper. The proposed UWB antenna has two stop bands which are achieved by using stepped impedance stub (SIS) loaded stepped impedance resonators (SIR) and SIS loaded hexagon stepped impedance resonators (HSIR). The switchable characteristics are obtained by employing two ideal switches on SISHSIR and SIS-SIR. By controlling the two switches ON and OFF, the proposed UWB antenna can work in multiple modes. The proposed switchable UWB antennas have been designed, analyzed, fabricated and measured. Simulated and experimental results show that the proposed antenna has switchable characteristics, tunable notch band functions and good radiation patterns. The proposed switchable UWB slot antenna can be used as a multi-mode antenna for multiple protocol communications. |
| Author(s): | Y. Li, W. Li, W. Yu |
| File Type: | Journal Paper |
| Issue: | Volume: 27 Number: 4 Year: 2012 |
| Download Link: | Click here to download PDF File Size: 1682 KB |
| Title: | A CPW Dual Band Notched UWB Antenna |
| Abstract: | In this paper, a coplanar waveguide (CPW)-fed microstrip antenna for ultra wideband application is presented. By using two branches of microstrip line and two slot lines on the antenna, two notches for interference bands has been created. The antenna has a rather compact structure; with total size of 25 × 25 × 1 mm3. This antenna covers bandwidth of more than 137% from 2.96 GHz to 16 GHz for S11< -10 dB. |
| Author(s): | M. Mighani, M. Akbari, N. Felegari |
| File Type: | Journal Paper |
| Issue: | Volume: 27 Number: 4 Year: 2012 |
| Download Link: | Click here to download PDF File Size: 1187 KB |
| Title: | Scattering from Large-Scale Stratified Rough Surfaces using Improved BMIA/CAG |
| Abstract: | A numerical method is presented to analyze the scattering behavior of large-scale stratified rough surfaces. The method improves the banded matrix iterative approach / canonical grid (BMIA/CAG) by adopting some simple formulas to calculate the coupling interactions between different surfaces. Such treatment reduces the complexity of the method at expense of little accuracy when the roughness of surfaces can be ignored compared to the distance between surfaces, and also reduces the computation time by parallel implementation technique. Based on emissivity calculation, the one-dimensional method is proven to be effective for the analysis of some scattering properties. Then the proposed method is compared with the method of moments (MoM) by example of multilayered lunar regolith. Details of numerical results are given and discussed, which provide a guide in the application of the improved method. |
| Author(s): | L. He, L. Lang, Q. Li, W. Zheng |
| File Type: | Journal Paper |
| Issue: | Volume: 27 Number: 4 Year: 2012 |
| Download Link: | Click here to download PDF File Size: 692 KB |
| Title: | Impact of Composite Materials on the Shielding Effectiveness of Enclosures |
| Abstract: | This paper investigates and compares the electromagnetic behavior of different shielding enclosures built with composite panels (dielectric materials with conducting inclusions, carbon-fiber, fiberglass, conductive materials). The numerical model is based on a full wave finite element method taking into account the geometrical details of the walls and avoiding the use of the classical equivalent layer approach. A 2D composite enclosure with two wall structures is modeled: fiber rods shielding and metal screen shielding. Impacts of conductivity and rod diameter on the shielding effect are investigated. Concerning metal screen, the shielding effectiveness is studied for different metals with the same mass, leading to identify the most effective metal. The influence of the angle of incidence and the number of apertures is also studied. Finally, a comparison is performed considering the same mass of the two composite wall structures, each composed of fiberglass and carbon fiber. |
| Author(s): | W. Abdelli, X. Mininger, L. Pichon, H. Trabelsi |
| File Type: | Journal Paper |
| Issue: | Volume: 27 Number: 4 Year: 2012 |
| Download Link: | Click here to download PDF File Size: 1123 KB |