ACES Publication Search





There are 15 search results for:



Title: ACES Journal March 2018 Cover
File Type: Journal Paper
Issue:Volume: 33      Number: 3      Year: 2018
Download Link:Click here to download PDF     File Size: 2168 KB

Title: ACES Journal March 2018 Front/Back Matter
File Type: Journal Paper
Issue:Volume: 33      Number: 3      Year: 2018
Download Link:Click here to download PDF     File Size: 379 KB

Title: ACES Journal March 2018 Full
File Type: Journal Paper
Issue:Volume: 33      Number: 3      Year: 2018
Download Link:Click here to download PDF     File Size: 11018 KB

Title: Wide-Angle Claerbout Scheme for Three-Dimensional Time Domain Parabolic Equation and its CN, ADI, AGE Solutions
Abstract: The wide-angle Claerbout scheme of three-dimensional time domain parabolic equation (Claerbout-TDPE) is derived in this paper, which can provide accurate results at angles within 25° of the paraxial direction. At first, the Crank-Nicolson (CN) type is introduced to discretize the Claerbout-TDPE. In this way, a three-dimensional EM scattering problem can be divided into a series of two-dimensional ones. Moreover, the alternating direction implicit (ADI) type is utilized to the Claerbout-TDPE. In this way, a three-dimensional EM scattering problem can be further reduced to a series of one-dimensional ones. Furthermore, the alternating group explicit (AGE) type is introduced to the Claerbout- TDPE for higher computational efficiency. Comparisons are made among the CN, ADI and AGE types in the numerical results.
Author(s): Z. He, H.-C. Yin, R.-S. Chen
File Type: Journal Paper
Issue:Volume: 33      Number: 3      Year: 2018
Download Link:Click here to download PDF     File Size: 1847 KB

Title: Phase-only Synthesis Algorithm for Transmitarrays and Dielectric Lenses
Abstract: In this work a phase-only synthesis algorithm is applied for the design of lens-array antennas yielding a desired radiation pattern. The potential relevance of spillover effect on the lens radiation pattern is illustrated, making it necessary to include it in the lens model and to take it into account in the synthesis algorithm. Thus, both the contribution of the lens and the spillover radiation are jointly modeled as a planar array. Moreover, in order to validate the algorithm, it has been applied to the synthesis of pixelated dielectric lenses, which have been simulated using a commercial software. Simulations show good agreement with the algorithm results, validating its use for this type of lenses.
Author(s): S. Loredo, G. Leon, O. F. Robledo, E. G. Plaza
File Type: Journal Paper
Issue:Volume: 33      Number: 3      Year: 2018
Download Link:Click here to download PDF     File Size: 2188 KB

Title: Determination of Physical Properties of Concrete by Using Microwave Nondestructive Techniques
Abstract: Determination of the electrical properties of concretes with different water/cement ratios and investigation of the relationship between their electrical and mechanical properties is a promising technique towards improving novel nondestructive microwave based methods. In this study, this relationship between water-cement ratios/mechanical properties and electrical characteristics of various concretes is investigated in the frequency range of 3-18 GHz. The obtained data provides an accurate measurement results for the researchers to design microwave sensors operating at a constant frequency. Besides, the relationship between the electrical properties and the pressure applied to the concrete is also investigated experimentally for various cement types. The experimental study demonstrates the presumable mechanical characteristic of the concrete by using its dielectric constant values. The dielectric constant is retrieved from the reflection and transmission coefficients (which are more commonly known as scattering parameters) by using Nicolson Ross Weir (NRW) Technique. It is revealed that the most significant frequency point is 18 GHz to determine water/cement ratio and 17 GHz to differentiate applied pressure level by using dielectric constant values of the concrete.
Author(s): M. Ozturk, U. K. Sevim, O. Akgol, E. Unal, M. Karaaslan
File Type: Journal Paper
Issue:Volume: 33      Number: 3      Year: 2018
Download Link:Click here to download PDF     File Size: 1824 KB

Title: Performance of Beamwidth Constrained Linear Array Synthesis Techniques Using Novel Evolutionary Computing Tools
Abstract: Antenna array synthesis for desired radiation characteristics is a challenging field of research in electromagnetics. When an array synthesis problem is visualized as an optimization problem several design parameters involved in synthesis process are considered as degrees of freedom. Every combination of design parameters forms a synthesis technique. In this paper, certain emphasis is given to analyse the techniques of linear array (LA) design using evolutionary computing tools. Novel computing tools like Flower Pollination Algorithm is used for LA synthesis using different degrees of freedom and compared with a conventional Tchebycheff method. Accelerated Particle Swarm Optimization (APSO) is also employed to study the consistency of the technique with the employed computing tool. Radiation patterns are generated with optimized SLL and Tchebycheff beamwidth constraint.
Author(s): C. S. R. Paladuga, C. V. S. S. S. Vedula, J. Anguera, R. K. Mishra, A. Andujar
File Type: Journal Paper
Issue:Volume: 33      Number: 3      Year: 2018
Download Link:Click here to download PDF     File Size: 1933 KB

Title: Extreme Learning Machine with a Modified Flower Pollination Algorithm for Filter Design
Abstract: In this paper, a modified flower pollination algorithm (FPA) based on the steepest descent method (SDM) is proposed to set the optimal initial weights and thresholds of the extreme learning machine (ELM) for microwave filter design. With the proposed SDMFPA, the model trained by the ELM can achieve higher accuracy with smaller training datasets for electromagnetic modeling, comparing to that achieved by traditional artificial neural network. The validity and efficiency of this proposed method is confirmed by a parametric modeling example of filter design.
Author(s): L.-Y. Xiao, W. Shao, S.-B. Shi, Z.-B. Wang
File Type: Journal Paper
Issue:Volume: 33      Number: 3      Year: 2018
Download Link:Click here to download PDF     File Size: 1718 KB

Title: Modelling of Interbranch Coupled 1:2 Tree Microstrip Interconnect
Abstract: A computational method of unbalanced single-input two-output (1:2) interconnect with coupled interbranch is introduced. The circuit theory is built with the topology constituted by the octopole Z-matrix represented by the coupled lines. The voltage transfer functions (VTFs) and the input impedance of the input-output electrical path of the unbalanced 1:2 tree with interbranch coupled lines are established. The computation model is verified with proofs of concept (POC) constituted by unbalanced 1:2 tree microstrip structure with and without interbranch coupled phenomenon. The POCs are loaded by resistors and capacitors. Good agreements between the simulated and modelled VTFs and the overall structure input impedances were obtained from 0.1-to-2 GHz.
Author(s): B. Ravelo, A. Normand, F. Vurpillot
File Type: Journal Paper
Issue:Volume: 33      Number: 3      Year: 2018
Download Link:Click here to download PDF     File Size: 2004 KB

Title: High Isolation UWB-MIMO Compact Micro-strip Antenna
Abstract: A compact four-unit ultra-wideband multipleinput multiple-output (UWB-MIMO) antenna with very high isolation, dual polarization, notched structure, and achieving dual-state operation, along with smaller volume, is proposed in this paper. The proposed MIMO antenna element consists of two parts: the front patch composed of four symmetrical trapezoidal radiating elements and feeder, and the back composed of a rectangular annular ground. The offset of antenna operating frequency band is achieved by adjusting the rectangular patch in the middle of the back side, and by introducing an X-shaped metal narrow strip on the top side and an X-shaped slit on the bottom side to improve the isolation in the single port feeding state of antenna. Finally, the dimension of the antenna is 32 × 32mm2. Under the frequency from 3.1 GHz to 10.6 GHz, the isolation in the condition of differential mode can below -30 dB, which is very high, and also can work in the single port inputting state, showing a dual mode operation. In addition, a trapezoidal slit is introduced to obtain a notch structure. The measured results and simulation results are consistent.
Author(s): Z.-L. Song, Z.-J. Zhu, L. Cao
File Type: Journal Paper
Issue:Volume: 33      Number: 3      Year: 2018
Download Link:Click here to download PDF     File Size: 2055 KB

Title: Performance of Multiple-Feed Metasurface Antennas with Different Numbers of Patch Cells and Different Substrate Thicknesses
Abstract: The design and performance of low-profile, multiple-feed metasurface antennas with different numbers of patch cells and different substrate thicknesses at a terahertz frequency are presented in this paper. The utilized antenna designs consist of a periodic array (N × M) metallic square-patch metasurface and a planar feeding structure, which are both patterned on an electrically thin, high-permittivity GaAs substrate. The antenna gain increased in a linear fashion with an increasing number of patch cells, which were directly fed by the slit feedline. A 3-dB gain increment was observed irrespective of the substrate thickness when the number of patch cells was doubled. However, the 3-dB gain bandwidth as well as the radiation efficiency changed significantly with varying substrate thicknesses. The described antenna structure offers useful characteristics by means of a combination of different substrate thicknesses and patch numbers. In addition, the proposed antenna design features a number of benefits, including a low profile, mechanical robustness, easy integration into circuit boards, and excellent suitability for low-cost mass production.
Author(s): N. Hussain, I. Park
File Type: Journal Paper
Issue:Volume: 33      Number: 3      Year: 2018
Download Link:Click here to download PDF     File Size: 1810 KB

Title: A Low Mutual Coupling MIMO Antenna Using Periodic Multi-Layered Electromagnetic Band Gap Structures
Abstract: A multi-layered electromagnetic band gap (EBG) structure is proposed and incorporated into a MIMO antenna to reduce unexpected mutual coupling between antenna elements. The proposed multi-layered EBG (ML-EBG) structure is comprised of an improved EBG and three loading patches with a same distance. The proposed ML-EBG structure is designed at 2.55 GHz and it is utilized in a MIMO antenna array with an edge-to-edge distance of 0.13 lambda to reduce the mutual couplings. The simulated and measured results have been put forward to prove that the mutual coupling has been reduced by 30 dB between the antenna elements compared to the MIMO antenna without the ML-EBG structure.
Author(s): T. Jiang, T. Jiao, Y. Li
File Type: Journal Paper
Issue:Volume: 33      Number: 3      Year: 2018
Download Link:Click here to download PDF     File Size: 1893 KB

Title: Polarization Insensitive Compact Chipless RFID Tag
Abstract: This research article proposes a highly dense, inexpensive, flexible and compact 29 x 29 mm2 chipless radio frequency identification (RFID) tag. The tag has a 38-bit data capacity, which indicates that it has the ability to label 238 number of different objects. The proposed RFID tag has a bar-shape slot/resonator based structure, which is energized by dual-polarized electromagnetic (EM) waves. Thus, portraying polarization insensitive nature of the tag. The radar cross-section (RCS) response of the proposed tag design is analyzed using different substrates, i.e., Rogers RT/duroid®/5880, Taconic (TLX- 0), and Kapton®HN (DuPontTM). A comparative analysis is done, which reveal the changes observed in the RCS curve, as a result of using different substrates and radiators. Moreover, the effect on the RCS response of the tag is also examined, by bending the tag at different bent radii. The compactness and flexible nature of the tag makes it the best choice for Internet of things (IoT) based smart monitoring applications.
Author(s): S. Zeb, A. Habib, J. A. Satti, Y. Amin, H. Tenhunen
File Type: Journal Paper
Issue:Volume: 33      Number: 3      Year: 2018
Download Link:Click here to download PDF     File Size: 2371 KB

Title: A Wideband Circular Polarization Antenna for UHF Tags
Abstract: In this paper, a low profile antenna for UHF Radio Frequency Identification (RFID) Tags with wideband circular polarization (CP) is proposed to solve the polarization mismatch in RFID systems. This antenna consists of two orthogonal dipole with unequal slots for realizing circular polarization radiation and a new matching network. For reducing size, a row-shaped tip loading is used. The measurement result of return loss bandwidth is 40 MHz (895-935 MHz) and 3-dB axial ratio bandwidth is 25 MHz (910-935 MHz). The overall size of antenna has been reduced to (0.19 lambda 0 × 0.19 lambda 0 × 0.005 lambda 0 ) at 915 MHz compared to previous works. Besides, other advantages of this design are wideband impedance matching and CP bandwidth.
Author(s): M. H. Zolghadri, S. Jam
File Type: Journal Paper
Issue:Volume: 33      Number: 3      Year: 2018
Download Link:Click here to download PDF     File Size: 2275 KB

Title: Genetic Algorithm Based Shape Optimization Method of DC Solenoid Electromagnetic Actuator
Abstract: This paper presents the method for the shape optimization of the DC solenoid electromagnetic actuator using a genetic algorithm. Numerical simulation of its transient response includes simultaneously solving differential equations of magnetic, electrical and mechanical subsystems. The magnetic subsystem is analyzed by finite element method (FEM), while the electrical and mechanical subsystems are modeled separately and mutually coupled. A modified genetic algorithm is programmed in MATLAB software package. The shape optimization has been performed on two-dimensional (2D) axial-symmetric model of electromagnetic actuator. The measurement results obtained after the production and testing of electromagnetic actuator are compared with results of numerical simulation.
Author(s): E. Plavec, I. Uglesic, M. Vidovic
File Type: Journal Paper
Issue:Volume: 33      Number: 3      Year: 2018
Download Link:Click here to download PDF     File Size: 2573 KB