International Journal of Applied Electromagnetics and Mechanics - Volume 47, issue 2

Authors: Weng, Yin-Kan | Li, Song | Yang, Jin-Ling | Zhou, Hui | Yi, Hong | Wang, Hong

Article Type: Research Article

Abstract: In this paper, a kind of efficient solution to the trihedral corner reflector's (TCR's) radar cross section (RCS) is proposed. Based on the combination of geometrical optics (GO) and Gordan surface integral method, TCR's RCS was computed and was compared with the results from computational electromagnetics software FEKO. Good agreement and significant speedup achieved show that the method mentioned in this paper is capable of practical rapid simulation and design, especially suitable for electrically large plate …structure. Show more

Keywords: Geometrical optics, gordan surface integral method, trihedral corner reflector, radar cross section, FEKO

DOI: 10.3233/JAE-130156

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 47, no. 2, pp. 533-539, 2015

Authors: Strecker, Z. | Roupec, J. | Mazůrek, I. | Klapka, M.

Article Type: Research Article

Abstract: Magnetorheological dampers seem to be suitable for the adaptive car suspension systems. For proper operation of the semi-active algorithms (skyhook, groundhook), the force response of the damper must be fast enough. In this paper, the response time of the Delphi vehicle MR damper is examined and the sources of the overall force time response on the control voltage are discussed. One of the main sources of the response time seems to be electro-magnetic circuit of the …MR damper. A principle of an optimal controller for reducing response of the coil's current on the control voltage is designed. However, the measured overall force time response with fast current controller was not reduced as expected. Therefore, a FEM simulation of the magnetic circuit was made. It shows that after an optimization of the current controller, eddy currents in the coil's core cause long time response and therefore they are the limiting factor of the response time of the MR damper. These simulations were verified by the measurements and some recommendations about improving the pistons construction are given at the end. Show more

Keywords: Magnetorheological damper, MR, time response, pulse-width modulation, eddy current

DOI: 10.3233/JAE-140006

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 47, no. 2, pp. 541-550, 2015

Authors: Chen, Junjie | Huang, Songling | Zhao, Wei

Article Type: Research Article

Abstract: In this paper, we propose an equivalent forward model of magnetic flux leakage (MFL) inspection in pipelines to reduce the computation effort to predict MFL signals. Then an iterative simulated annealing inversion procedure is developed to reconstruct the three-dimensional (3-D) defect profile from MFL signals. Experiments results, based on both simulated and measured MFL signals, demonstrate that the proposed inversion procedure using the equivalent forward model has high performance in terms of execution speed and accuracy.

Keywords: Magnetic flux leakage, equivalent model, defect reconstruction, pipeline inspection, simulated annealing algorithm

DOI: 10.3233/JAE-140022

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 47, no. 2, pp. 551-561, 2015

Authors: Patel, Amit | Kosta, Y.P.

Article Type: Research Article

Abstract: This paper presents a novel transversal coupling network for the design of multiple-band bandstop filters. In this proposed structure, multiple-band bandstop filter is design based on amalgamated (conductive and dielectric material) posts coupled rectangular waveguide to demonstrate the feasibility of proposed network. We have proposed two structures using four metallic windows placed at the corners of triangle inside a waveguide and symmetrical dielectric material posts placed at the center of the triangle made …by metallic posts. By inserting dielectric post, the results are improved. The structures are simulated with Ansoft's finite-element High Frequency Structure Simulator tool and its equivalent circuit of Ansoft designer to demonstrate the characteristics of this notch filter using a rectangular waveguide with center frequency of 11.2 GHz. The proposed structure using amalgamated post is fabricated and tested using the Vector Network Analyzer and obtained results compared with the simulated results. Show more

Keywords: Conductive {and} dielectric posts, waveguide resonator, scattering parameters, rejection bandwidth {and} quality factor

DOI: 10.3233/JAE-130158

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 47, no. 2, pp. 563-581, 2015