International Journal of Applied Electromagnetics and Mechanics - Volume 47, issue 3

Authors: Naeem, Nadeem | Ismail, Alyani | Alhawari, Adam Reda Hassan | Mahdi, Mohd Adzir

Article Type: Research Article

Abstract: This study reports new shape of meta-material array structures having electric and magnetic resonances designed for terahertz (THz) frequency band. The proposed structures exhibit left handed meta-material propertiesin THz frequency band. The introduced meta-material split ring resonators in this paper are constructed using a single loop of conducting wire strip printed over a very thin low permittivity polyimide dielectric substrate. The effective parameters like permeability and negative index are extracted from the …simulated complex scattering parameters using direct retrieval method. Unloaded Q-factor is calculated for proposed terahertz metamaterial resonators. The proposed arrays are tested by loading different dielectric samples in order to confirm the testing capability. Significant shift in the transmission is observed. The reported array structures are novel in terms of their left handed behavior in THz frequencies. High values of Q-factor reported here, are suitable for near field sensing applications. Show more

Keywords: Metamaterial array, permeability, negative index, terahertz, near field, dielectric sensing

DOI: 10.3233/JAE-140107

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 47, no. 3, pp. 827-836, 2015

Authors: Wang, Jingang | Yang, Jie | Luo, Ruixi

Article Type: Research Article

Abstract: Online transformer monitoring and protective relaying require voltage sensors with fast response and high precision. Traditional devices, such as resistive and capacitive dividers, have disadvantages in measuring transient voltage, e.g., oscillation, narrow bandwidth, and large size. This paper introduces a new D-dot probe for transient measurement. The difference input circuit structure is presented on the basis of the operating principle of the D-dot probe. Paralleled multiple electrodes are applied to gain the mutual …capacitance value of the probe to achieve a large divide ratio and make the probe work in a self-integrating mode. Pspice simulation is conducted to find a way to minimize probe error. The probe is manufactured into printed circuit boards (PCB). The steady state linearity and transient response of the probe are tested. Results show that the probe has fast response and broad bandwidth. Show more

Keywords: Transient voltage measurement, D-dot probe, self-integrating, printed circuit boards electrodes

DOI: 10.3233/JAE-140111

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 47, no. 3, pp. 837-845, 2015

Authors: Ye, Zhitong | Duan, Zhiyong | Su, Liushuai | Takahata, Kenichi | Su, Yufeng

Article Type: Research Article

Abstract: This paper presents theoretical analysis and verification of a micro vibration energy harvester based on magnetic levitation using diamagnetic structures. The analysis verifies that diamagnetic material experiences anti-magnetic force in magnetic field and that it can be used for stable magnetic levitation. This study proposes a novel design that is comprised of a lifting permanent magnet, an upper pyrolytic graphite sheet, a floating permanent magnet, and a lower pyrolytic graphite sheet, with copper spiral …coils formed on the two pyrolytic graphite sheets. The gravity of the floating permanent magnet is balanced by the attractive force between the lifting and floating magnets. The diamagnetic force exerted on the levitated magnet by the two pyrolytic graphite sheets serves as a restoring force, forcing the floating permanent magnet return to the equilibrium position. Through finite element analysis, the maximum movable range of the floating magnet is defined to be 1.3 mm. Comparative analysis of the attractive magnetic force and the anti-magnetic force is performed to determine the key parameters of the structure. The characteristics of vertical and horizontal motion of the magnet are also studied in detail. The results validate the effectiveness of the proposed design for harvesting multi-dimensional, low-frequency vibration energy. The diamagnetic levitation mechanism without conventional mechanical suspensions eliminates loss of vibration energy and resultant thermal issues. The system is potentially promising, through further miniaturization, in providing sustainable power for micro-electro-mechanical systems. Show more

Keywords: Micro-vibration energy harvester, diamagnetic, levitation, multi-dimension, micro-electro-mechanical system (MEMS)

DOI: 10.3233/JAE-140120

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 47, no. 3, pp. 847-860, 2015

Authors: Hu, Chao | Sun, Yue | Lv, Xiao | Wang, Zhihui | Xiong, Qingyu

Article Type: Research Article

Abstract: Magnetic coupler is the most critical part to achieve high power transmitting capability in an inductive power transfer (IPT) system. This paper introduces a design procedure of magnetic coupler. Based on the design procedure, the main parameters that affect the output power and power loss of the magnetic coupler have been found. In order to stable the operating frequency, equations which calculate the receiver self-inductance and the magnetic coupler mutual inductance are developed and analyzed. Moreover, …the parameters of Double-Layer-Double-D (DLDD) coil which is designed for electric vehicles' (EVs') wireless charging are derived according to the magnetic coupler design procedure. The experimental results show that the power transfer efficiency (PTE) of an IPT system with DLDD coil can be as high as 85.1% with a transmitting distance of 15 cm, while the output power is 10 kW. Show more

Keywords: Inductive power transfer (IPT), electric vehicle (EV), magnetic coupler, design procedure

DOI: 10.3233/JAE-140146

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 47, no. 3, pp. 861-873, 2015