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Title: ACES Journal November 2013 Full Issue
File Type: Journal Paper
Issue:Volume: 28      Number: 11      Year: 2013
Download Link:Click here to download PDF     File Size: 16633 KB

Title: ACES Journal November 2013 Front/Back Matter
File Type: Journal Paper
Issue:Volume: 28      Number: 11      Year: 2013
Download Link:Click here to download PDF     File Size: 2717 KB

Title: Hybrid Binary-Real GA Optimization Approach for Breast Microwave Tomography
Abstract: A microwave tomography imaging system, which uses a hybrid binary-real genetic algorithm (GA) is described in this work. This method utilizes global optimization for solving the inverse scattering problem based on hybrid version of GA, which is the combination of both real and binary-coded GA. This method is principally aimed at breast imaging for the detection of malignant tumors. The proposed technique is based on a time-domain inverse solver, which uses the multi-illumination technique and includes the dispersive and heterogeneous characteristic of the breast tissues. In this algorithm, real-coded GA acts as a regularizer for binary-coded GA and rejects the non-true solutions. The proposed technique is validated using a numerical breast phantom created based on magnetic resonance imaging (MRI) of actual patients. The results are compared with non-hybrid binary and real GAs and the superior efficiency of the proposed method over the methods that solely employ real or binary GA is illustrated.
Author(s): A. Sabouni, A. Ahtari, S. Noghanian, G. Thomas , S. Pistorius
File Type: Journal Paper
Issue:Volume: 28      Number: 11      Year: 2013
Download Link:Click here to download PDF     File Size: 767 KB

Title: Imaging 2D Breast Cancer Tumor Margin at Terahertz Frequency using Numerical Field Data based on DDSCAT
Abstract: This work presents tomography of breast cancer tumor margins in the terahertz frequency band. The discrete dipole approximation is employed to calculate the electromagnetic fields scattered from simulated heterogeneous breast tumors. Two-dimensional Comedo with necrotic core and papillary breast tumor patterns are computer-generated for this investigation. The Rytov approximation is applied to terahertz scattered field data calculated at a line of receivers in the far field from the samples. The obtained tomography images demonstrate a potential for terahertz frequency for identifying and assessment of breast cancer tumor margins.
Author(s): T. C. Bowman, A. M. Hassan, M. El-Shenawee
File Type: Journal Paper
Issue:Volume: 28      Number: 11      Year: 2013
Download Link:Click here to download PDF     File Size: 1222 KB

Title: Synthesis of Conical Conformal Array Antenna Using Invasive Weed Optimization Method
Abstract: Invasive weed optimization (IWO), which shows high performance in the electromagnetic community, is used to synthesize the conical conformal array antenna in this paper. Radiation pattern of the conformal array antenna is obtained by the superposition of the active element radiation pattern in the presence of platform, which includes the mutual coupling information of the array antenna and effects of the platform. Compared with partial swarm optimization (PSO), performance of IWO is more stable and lower side-lobe is obtained with IWO. A linear antenna array mounted on conical carrier is optimized and fabricated, measured results agree well with the optimized results. In addition, the proposed method can be used for the pattern synthesis of any kind of antenna array.
Author(s): Y. Li, F. Yang, J. Ouyang, P. Yang
File Type: Journal Paper
Issue:Volume: 28      Number: 11      Year: 2013
Download Link:Click here to download PDF     File Size: 1156 KB

Title: Fast Calculation of 3D Conductive Target Backscatter in a Random Medium using Coherence Based Monte Carlo Integration (CBMI) Method
Abstract: IN THIS PAPER, A FAST METHOD TO PERFORM BACKSCATTERING CALCULATIONS FROM PERFECT ELECTRICALLY CONDUCTING (PEC) OBJECTS EMBEDDED IN CONTINUOUS RANDOM MEDIA IS PRESENTED. THE CURRENT GENERATOR METHOD (CGM) IS REVISITED AND IS MODIFIED FOR SPEED, REMOVING THE NEED TO PERFORM MATRIX INVERSE OPERATIONS. THE PRESENTED FORMULATIONS ARE ADEQUATE TO SOLVE TWO AND THREE DIMENSIONAL PROBLEMS. MONTE CARLO TECHNIQUE WILL BE EMPLOYED TO SPEED THE HIGH ORDERED INTEGRATION BY USING THE DE-CORRELATION IN SPACE FOUND WITHIN THE FOURTH MOMENT OF GREEN'S FUNCTION AS AN 'IMPORTANCE SAMPLING' DISTRIBUTION. THIS INCOHERENCEIS EXPLICITLY SHOWN IN THE CURRENT GENERATOR FORMULATION. THE REVISITED FORMULATION HAS IMPROVED FUNCTIONALITY IN ITS ABILITY TO CONSIDER THREE DIMENSIONAL OBJECTS. ITS ALGORITHMIC PERFORMANCE IS ANALYZED AND IS FOUND TO BE SIGNIFICANTLY FASTER THAN OTHER CANDIDATE MATRIX BASEDMETHODS.
Author(s): G. Togtema, H. El-Ocla, M. Al Sharkawy
File Type: Journal Paper
Issue:Volume: 28      Number: 11      Year: 2013
Download Link:Click here to download PDF     File Size: 243 KB

Title: A Novel Approach to Synthesis of Non-uniform Conformal Reflectarray Antennas
Abstract: This paper presents an accurate method to synthesize a shaped-beam conformal reflectarray (RA) antenna based on the phase synthesis of its equivalent aperture. For this purpose particle swarm optimization (PSO) is used to determine the optimal phase distribution on the reflective surface of the antenna. Furthermore, a method based on meshing the aperture of the antenna has been adopted to evaluate its radiation fields. By dividing the equivalent aperture of the antenna into small parts, the induced current in each part is approximated appropriately.Then the radiation fields can be evaluated via the sum of simple integrals. This approach provides a direct correlation between the amplitude and the phase of reflection coefficient of the RA elements with the radiation fields of the antenna. Therefore, the effect of elements can be considered directly in the optimization process. Another advantage of this method is that it can be used to synthesize non-flat RA antennas. Furthermore, in the proposed method the effects of the angle, polarization, amplitude, and phase of the radiated fields from the feed antenna are fully considered in the synthesis procedure. To verify the proposed method a shaped beam parabolic RA antenna in the X-band has been synthesized. The simulation results represent a good agreement with the simulation results obtained from the commercial full-wave electromagnetic (EM) software, CST microwave studio.
Author(s): M. Karimipour, A. Pirhadi
File Type: Journal Paper
Issue:Volume: 28      Number: 11      Year: 2013
Download Link:Click here to download PDF     File Size: 888 KB

Title: Novel Bandwidth-Agile Bandpass Filter using Defected Ground Structure
Abstract: A novel microstrip bandpass filter (BPF) with tunable passband width using defected ground structure (DGS) is proposed. In this DGS, a pair of slotted radial stubs that can be equivalent to a capacitor and an inductor in parallel are incorporated to realize an attenuation pole (AP) in the higher stopband of the proposed BPF without increasing the circuit size, and the equivalent circuit of the BPF is also given. By properly adding varactor diodes into the slotted stubs to tune the equivalent capacitance of the stubs, the corresponding AP can be shifted, and then the passband width of the BPF can be accordingly tuned, leading to a bandwidth-agile BPF.
Author(s): Z. H. Bao, Q. Y. Lu, C. Shao, J. X. Chen, S. Zhang
File Type: Journal Paper
Issue:Volume: 28      Number: 11      Year: 2013
Download Link:Click here to download PDF     File Size: 710 KB

Title: Square Dual-Mode Quasi-Elliptic Bandpass Filter with Wide Upper Stopband
Abstract: A square dual-mode quasi-elliptic bandpass filter (BPF) with a wide stopband is proposed. To realize the quasi-elliptic response and harmonic suppression for the filter, the inductive source-load coupling is introduced. To achieve wider stopband suppression, the open-circuited stubs are adopted. A demonstration filter with 3-dB fractional bandwidth (2.84 GHz - 3.28 GHz) about 14.3 % has been designed, fabricated, and measured. Simulated and measured results indicate that the proposed filter can effectively suppress 6th harmonic response referred to a suppression degree of 16.5 dB.
Author(s): Y. Ma, W. Che, W. Feng, J. X. Cheng
File Type: Journal Paper
Issue:Volume: 28      Number: 11      Year: 2013
Download Link:Click here to download PDF     File Size: 286 KB

Title: Analysis of a Novel Ka Horn Antenna with Low Cross-Polarization
Abstract: A Ka combined horn antenna with low cross-polarization is presented in this paper. The antenna consists of an edge-slotted waveguide linear array, a metallic-grid plane in the horn throat and a horn. The effects of metallic-grid and single-ridged waveguide to the cross-polarization are analyzed. Three kinds of 62-element Taylor linear array at Ka band are fabricated and measured and the measured cross-polarization level is less than -35dB in operating bandwidth. The proposed antennas are benefit for fabrication and fixation with low cross-polarization and can be extensively used in radar and communication systems.
Author(s): Y. Z. Liu, S. Xiao, B. Z. Wang
File Type: Journal Paper
Issue:Volume: 28      Number: 11      Year: 2013
Download Link:Click here to download PDF     File Size: 1180 KB

Title: An Unequal Wilkinson Power Divider using Half Mode Substrate Integrated Waveguide
Abstract: A new unequal Wilkinson power divider is presented in this paper. The structure benefits from half mode substrate integrated waveguide (HMSIW). In order to increase the characteristic impedance of the HMSIW line, an inductive post is used in the line. Different dividing ratios are obtained by changing the diameter of the inductive post. The experimental results show that the power dividing ratio is 5.1:1 over the frequency range of 9.1 GHz to 12.8 GHz. The input and output ports are well-matched and the output ports are isolated from each other over this frequency range. The experimental results and simulation results of CST Microwave Studio are in good agreement.
Author(s): Z. Mazani, G. Moradi
File Type: Journal Paper
Issue:Volume: 28      Number: 11      Year: 2013
Download Link:Click here to download PDF     File Size: 0 KB

Title: Simple and Compact Dual Band-Notched Monopole Antenna Using U-Shaped Forms on the Conductor-backed Plane for UWB Applications
Abstract: A planar ultra-wideband antenna with dual band-notched characteristics is proposed. The main features of the proposed antenna are the extremely compact dimensions and band-notched characteristics that are obtained without modifying the radiator. The dual band-notched characteristics are achieved by a pair of mirror U-shaped slots and an inverted U-shaped slot at the conductorbacked plane. The measured results of the manufactured (15 mm 15 mm) antenna on 1.6 mm FR4 substrate show that the antenna operates with VSWR less than two over the frequency band from 3 GHz to 11.2 GHz. That wideband is featured by the existence of two notched bands VSWR is more than five aimed at suppressing any interference from IEEE802.11a WLAN 5 GHz (5.15 GHz - 5.825 GHz) and ITU 8 GHz (8.025 GHz - 8.4 GHz) band. The antenna has a desirable VSWR level, radiation pattern, and gain characteristics for ultra wideband frequency band range.
Author(s): M. Moosazadeh, Z. Esmati
File Type: Journal Paper
Issue:Volume: 28      Number: 11      Year: 2013
Download Link:Click here to download PDF     File Size: 2656 KB

Title: Hybrid Electric Vehicle Characterization Using Generalized Notion of Power
Abstract: This paper presents a novel mathematical model based on the generalized notion of power (GNP) to accurately predict the performance characteristics of hybrid electric vehicles (HEVs). The uniqueness of this technique is the ability to represent both internal combustion engine and electrical propulsion machines in one system of state space equations. Thus, it allows proper characterization and control of the interaction of both systems by taking into account large and small load disturbances and the irreversibility of entropy generation by the internal combustion engine. The superiority of the proposed model is demonstrated by applying it to a prototype HEV configuration and by comparison to readily available benchmark data.
Author(s): N. Al-Aawar, A. A. Arkadan
File Type: Journal Paper
Issue:Volume: 28      Number: 11      Year: 2013
Download Link:Click here to download PDF     File Size: 440 KB

Title: An Equivalent Model for Wiring Harness Induced Current in Automobiles
Abstract: This paper presents an equivalent model for the simulation of the induced current along wiring harnesses in automobiles. The equivalent model is based on multi-transmission line theory. Then, this model is simulated by using the commercial FEM software, HFSS. The common-mode current simulation results show that the presented method is effective and the equivalent model can reduce the computation time and complexity of the wire harness model. Finally, the proposed equivalent method is proved by experiment. The equivalent model can handle automotive wiring harness for electromagnetic radiation sensitivity problems in the high frequency range.
Author(s): Y. Zheng, Q. Wang, G. Wang, Z. An, Q. Liu, X. Li
File Type: Journal Paper
Issue:Volume: 28      Number: 11      Year: 2013
Download Link:Click here to download PDF     File Size: 921 KB

Title: Effective Analysis of Ridged Circular Waveguides with a Curvilinear Frequency-Domain Finite-Difference Approach
Abstract: We present a frequency domain finite difference approach in curvilinear coordinates to the computation of the modes of circular ridged waveguides. The use of a polar mesh allows to avoid staircase approximations of the boundary, providing a very effective and accurate procedure. The proposed approach has been assessed, both in terms of accuracy and effectiveness, against general-purpose software, namely CST Microwave Studio and Ansys HFSS, showing a significant reduction of the computational burden.
Author(s): A. Fanti, G. Montisci, G. Mazzarella, G. A. Casula
File Type: Journal Paper
Issue:Volume: 28      Number: 11      Year: 2013
Download Link:Click here to download PDF     File Size: 488 KB

Title: Extended Scheme using Equivalent Dipoles for Characterizing Edge Currents Along a Finite Ground Plane
Abstract: For the assessment of radiated fields, a simplified analytical solution that approximates the effects of the currents induced at the edges of a finite ground plane is presented. These edge currents are induced by the actual current sources on the plane. This method can be used in characterizing the electromagnetic (EM) emission from any practical PCB and avoids the need for using high-frequency techniques in evaluating effects due to diffraction.
Author(s): C. Obiekezie, D. W. Thomas, A. Nothofer, S. Greedy, L. R. Arnaut, P. Sewell
File Type: Journal Paper
Issue:Volume: 28      Number: 11      Year: 2013
Download Link:Click here to download PDF     File Size: 465 KB

Title: Issues in Antenna Optimization - A Monopole Case Study
Abstract: A typical antenna design optimization problem is presented, and various issues involved in the design process are discussed. Defining a suitable objective function is a central question, as is the type of optimization algorithm that should be used, stochastic versus deterministic. These questions are addressed by way of an example. A single-resistor loaded broadband HF monopole design is considered in detail, and the resulting antenna compared to published results for similar continuously loaded and discrete resistor loaded designs.
Author(s): R. A. Formato
File Type: Journal Paper
Issue:Volume: 28      Number: 11      Year: 2013
Download Link:Click here to download PDF     File Size: 2809 KB