International Journal of Applied Electromagnetics and Mechanics - Volume 35, issue 3

Authors: Ourabia, Malika | Touhami, Rachida | Baudrand, Henri

Article Type: Research Article

Abstract: In this paper, the authors proposed a new approach for efficient planar multiport junction design using the concept of edge line and the boundary-element method. The S-parameters are obtained by a simple identification in a system of equations given by the boundary method. In addition to a reduction in the CPU time, the proposed method can easily handle complicated structures. The method is verified by comparison to previous work on junctions.

Keywords: Boundary-element, discontinuities, edge line, planar waveguide

DOI: 10.3233/JAE-2011-1328

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 35, no. 3, pp. 151-163, 2011

Authors: Stojanović, Goran | Lečić, Nikola | Damnjanović, Mirjana | Živanov, Ljiljana

Article Type: Research Article

Abstract: In this paper we investigate microstructure and electrical properties of NiZn ferrite ring cores and influence of different temperatures on these properties in the wide frequency range from 10 kHz to 1 GHz. Important electrical parameters are analyzed through measuring inductance, impedance and phase angle using LCZ meter HP4277A for lower frequency range (10 kHz–1 MHz) and RF Impedance analyzer HP4191A for higher frequencies (1 MHz–1 GHz). The complex permeability spectra of two ferrite materials, labeled …with F14 and F19, has been calculated by means of these measured parameters. It can be concluded that, up to a certain frequency, permeability increases with temperature increase and above that frequency this behavior is opposite. The normalized temperature characteristics of permeability and impedance are also given for analyzed samples. Show more

Keywords: NiZn ferrites, complex permeability, temperature dependence

DOI: 10.3233/JAE-2011-1329

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 35, no. 3, pp. 165-176, 2011

Authors: Liu, Bo | Jiang, Qing | Yang, Jiashi

Article Type: Research Article

Abstract: We study thickness-shear vibration of a rotated Y-cut quartz crystal plate whose one surface is in contact with a viscous fluid layer of finite thickness. The fluid is under an electrode separated from the crystal plate and the driving electric field is in the plate thickness direction. The theory of piezoelectricity and the theory of Newtonian fluids are used. Both free and forced vibration solutions are obtained. An approximate expression for the frequency shifts in the …crystal plate due to the fluid is presented. The admittance of the structure is also calculated. The results are useful for acoustic wave fluid sensors. Show more

DOI: 10.3233/JAE-2011-1330

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 35, no. 3, pp. 177-187, 2011

Authors: Yixiang, Bian | Jinhao, Qiu

Article Type: Research Article

Abstract: The metal core piezoelectric fiber (MPF) is one of the new type piezoelectric devices for sensors and actuators. To investigate the dynamic characteristics of a cantilever MPF, the dynamic admittance matrix is established. It can describe the response of a cantilever MPF subjected to driving parameters, a harmonically varying axial force F at the tip and a harmonically varying voltage V on the electrodes. The responses parameters of a cantilever MPF, including a dynamic tip elongation …δ and a dynamic electric charge Q, can be obtained using the vibration theory and the average distributed electrical charge method. The response parameters are related to the driving parameters by a 2 × 2 matrix. The dynamic models for measuring piezoelectric parameters of a MPF are given in order to illustrate the applications of the previous dynamic admittance matrix. The piezoelectric parameters, the elastic coefficient s_{11}^E , the piezoelectric coefficient d_{31} and the dielectric constant ε _{33}^T of MPF were measured experimentally. Show more

Keywords: Metal core, piezoelectric fiber, dynamic admittance matrix, piezoelectric parameters, measurement

DOI: 10.3233/JAE-2011-1332

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 35, no. 3, pp. 189-200, 2011

Authors: Xu, Lizhong | Sun, Libo

Article Type: Research Article

Abstract: In the vibration system consisting of the micro plate, electric field and fluid film, the electrostatic force and the fluid film pressure play important role. To consider the effects of the electrostatic force and fluid film pressure on the micro plate vibration, an electromechanical-fluidic coupled dynamics model should be developed. It is a multi-field coupled dynamics problem. Here, the nonlinear electromechanical-fluidic coupled dynamic equations of the micro plate subjected to the electrostatic force and the fluid …film pressure are derived. Using KBM method, the nonlinear multi-field coupled dynamic equations are resolved. Meanwhile, the equations of the electric field and the fluid pressure fluctuations are presented. Using these equations, the nonlinear multi-field coupled free vibration and the forced responses of the micro-plate are analyzed. Results show that the electrostatic force and the fluid film pressure have obvious effects on the dynamic displacements of the micro-plate, and the dynamic displacements of the micro-plate can cause fluctuations of the electrostatic force and the fluid film pressure. These results are useful in the design and manufacture of such MEMS. Show more

Keywords: Dynamics, micro plate, MEMS, natural frequency, multi-field coupling

DOI: 10.3233/JAE-2011-1333

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 35, no. 3, pp. 201-229, 2011