International Journal of Applied Electromagnetics and Mechanics - Volume 47, issue 4

Authors: Di Barba, Paolo | Forzan, Michele | Sieni, Elisabetta

Article Type: Research Article

Abstract: In the paper, a benchmark in the field of induction heating is described in order to test optimization methods. The optimal design of a pancake inductor for the controlled heating of a graphite disk is considered. The direct problem is characterized by a coupledmagneto-thermal field analysis.

Keywords: Multiobjective optimization, finite elements, induction heating, coupled problems, benchmark

DOI: 10.3233/JAE-140108

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 47, no. 4, pp. 1003-1013, 2015

Authors: Zuo, Shao-Li | Zhang, Zhi-Ya | Wu, Wei-Jun

Article Type: Research Article

Abstract: A wideband dual-polarized crossed-dipole antenna with shorted stubs for base station applications is presented. By using a pair of orthogonal crossed-dipole, two linear polarizations (± 45°) are obtained. The shorted subs are introduced to improve the impendence bandwidth and enhance the isolation (S12 ) between the two orthogonal polarizations. The antenna shows a wideband impedance characteristics of about 29.4% for S11 ≤-10 dB (+45° polarization) and S22 ≤ -10 dB (-45° polarization). High isolation (S12 ≤ -32 dB) between the two polarizations in the required band is obtained, which the lowest isolation is only -56 dB at about 1.8 GHz. …The stable peak gain, unidirectional radiation patterns, low cross-polarization and high front-to-back ratio over the whole operating band are also achieved. Due to its good performance, the antenna is very suitable for potential base station applications in mobile communication such as DCS, PCS and UMTS. Show more

Keywords: Dual-polarized antenna, bowtie dipole, wideband antenna, base station

DOI: 10.3233/JAE-140110

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 47, no. 4, pp. 1015-1022, 2015

Authors: Shui, Guoshuang | Li, Changwu | Yao, Kai

Article Type: Research Article

Abstract: Based on the measurement of residual magnetic spontaneous stray field, metal magnetic memory (MMM) technique is an effective method in evaluating the degree of early damage for ferromagnetic materials due to the existence of stress concentration. In this paper, the normal and tangential components of the stress induced self-magnetic leakage field (SMLF) intensity on the surface of specimens were measured at predetermined tensile forces throughout the tensile process. The results show that the stress induced normal and tangential components of the self-magnetic leakage field are effective in characterizing different stress levels in elastic deformation stages; and the tangential component is …more effective in characterizing different plastic deformation stages. Furthermore, experimental measurements using nonlinear ultrasonic technique (NUT) were also conducted at the same stress level when the magnetic memory signals were collected. It shows that MMM technique is effective in charactering the stress-strain state in elastic deformation stage for ferromagnetic materials; and NUT is effective in charactering the degree of plastic deformation. Show more

Keywords: Metal magnetic memory (MMM), nonlinear ultrasonic technique (NUT), damage, non-destructive evaluation

DOI: 10.3233/JAE-140115

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 47, no. 4, pp. 1023-1038, 2015

Authors: Samsuzzaman, M. | Islam, M.T. | Nahar, M.K. | Mandeep, J.S. | Mansor, F. | Islam, M.M.

Article Type: Research Article

Abstract: A circular polarized highly directional S band patch antenna for small satellite applications has been proposed in this invention. The proposed antenna comprises of a square ground plane and two circular radiating patches with annular circular slot fed by a coaxial probe. The circular slot in the radiating patch is responsible for creating resonance at the S band. The prototype is can be easily integrated with a small satellite due to the simplicity of the design. The modification of the circular shape patch by cutting circular shape slots help to excite the resonance at the desired frequency. The simulation and …the experimental results have a good agreement. The proposed antenna has achieved an impedance bandwidth of 55 MHz (2.380 GHz-2.435 GHz) and axial ratio (AR) < 3 dB is about 35 MHz (2.410 MHz-2.445 MHz) in the operating band. The prototype has achieved a gain of 8.13 dBi at centre frequency of 2.42 GHz. The directional radiation pattern, circular polarization (CP), and high gain characteristics make the proposed antenna suitable for small satellite applications. Show more

Keywords: Circularly polarized, CubeSat applications, circular patch, directional antenna, and high gain, slotted

DOI: 10.3233/JAE-140147

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 47, no. 4, pp. 1039-1049, 2015

Authors: Giorgio, Ivan | Galantucci, Luca | Della Corte, Alessandro | Del Vescovo, Dionisio

Article Type: Research Article

Abstract: This review paper intends to gather and organize a series of works which discuss the possibility of exploiting the mechanical properties of distributed arrays of piezoelectric transducers. The concept can be described as follows: on every structural member one can uniformly distribute an array of piezoelectric transducers whose electric terminals are to be connected to a suitably optimized electric waveguide. If the aim of such a modification is identified to be the suppression of mechanical vibrations then the optimal electric waveguide is identified to be the `electric analog' of the considered structural member. The obtained electromechanical systems were called PEM …(PiezoElectroMechanical) structures. The authors especially focus on the role played by Lagrange methods in the design of these analog circuits and in the study of PEM structures and we suggest some possible research developments in the conception of new devices, in their study and in their technological application. Other potential uses of PEMs, such as Structural Health Monitoring and Energy Harvesting, are described as well. PEM structures can be regarded as a particular kind of smart materials, i.e. materials especially designed and engineered to show a specific and well-defined response to external excitations: for this reason, the authors try to find connection between PEM beams and plates and some micromorphic materials whose properties as carriers of waves have been studied recently. Finally, this paper aims to establish some links among some concepts which are used in different cultural groups, as smart structure, metamaterial and functional structural modifications, showing how appropriate would be to avoid the use of different names for similar concepts. Show more

Keywords: Piezoelectric transducers, vibration and sound radiation control, electric analog, structural health monitoring, energy harvesting

DOI: 10.3233/JAE-140148

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 47, no. 4, pp. 1051-1084, 2015

Authors: Shen, Su-Mei | Chen, I-Fong | Peng, Chia-Mei | Lin, Ding-Bing

Article Type: Research Article

Abstract: The analysis of multi-band operation of printed co-planar waveguide (CPW) feed monopole antenna was presented in this paper. The ground-strip of the CPW structure was regarded as a low impedance path for returning currents with constant potential across its area, but it is not a perfect-ground, it has significant reactance to act a radiator for the related frequency. Therefore, based on the Gaussian Filter Model (GFM), the quantitative values of inductance and capacitance of the proposed antenna will be derived from the decomposed CPW structure. Measured and Ansoft HFSS simulation results are presented to confirm the results which are obtained …by using decomposed GFM. Moreover, the asymmetric ground-strip of CPW is also experimentally investigated. Experimental results are shown to verify the validity of theoretical work. Show more

Keywords: Multi-band operation, printed monopole, co-planar waveguide, imperfect ground, GFM

DOI: 10.3233/JAE-140156

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 47, no. 4, pp. 1085-1092, 2015

Authors: Boumaiza, Mostefa | Labed, Djamel

Article Type: Research Article

Abstract: In this work we study the coupling of a lightning wave with an overhead power distribution lines. The study is led directly in the time domain with hold in account of the effect of a finite conductivity of the soil. By the classic method poses a problem of digital heaviness linked to the spatial discretization and taking into account the electrical conditions at the ends of nodes and connections. The formalism that we propose overcomes the spatial discretization taking into account the electromagnetic aggression along each conductor and the electrical conditions at the ends allowing us to deduce the currents …and voltages induced in every node of the line directly. After discretization by the method so-called FDTD (Finite Difference Time Domain) of the lines equations excited by a lightning wave and the application in every node of the network of the Kirchhoff's laws in current and voltage, we deduct a equations system linear or no, of which the resolution permits us to deduct the induced electric quantities in every node of the network. In this study we propose a concept for the coupling analysis of a lightning wave with an overhead line without use of the least FFT. In order to confirm our theoretical work, we present a set of applications that allows validating this study. Show more

Keywords: Power distribution lines, lightning, electromagnetic field, ground transient resistance, induced voltage

DOI: 10.3233/JAE-140144

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 47, no. 4, pp. 1093-1106, 2015

Article Type: Other

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 47, no. 4, pp. 1107-1116, 2015