Arbitrary Magnetic Field Control Technique by Multi-Coil Transmitter Voltage Phase Shifting for Omni-Directional Free-Positioning Magnetic Resonance Wireless Power Delivery

This research paper presents the design of a wireless power transfer (WPT) circuit integrated with magnetic resonance coupling (MRC) and harvested radio frequency (RF) energy to wirelessly charge the battery of a mobile device. A capacitor (100 µF, 16 V) in the RF energy harvesting circuit stored the converted power, and the accumulated voltage stored in the capacitor was 9.46 V. The foundation of the proposed WPT prototype circuit included two coils (28 AWG)—a transmitter coil, and a receiver coil. The transmitter coil was energized by the alternating current (AC), which produced a magnetic field, which in turn induced a current in the receiver coil. The harvested RF energy (9.46 V) was converted into AC, which energized the transmitter coil and generated a magnetic field. The electronics in the receiver coil then converted the AC into direct current (DC), which became usable power to charge the battery of a mobile device. The experimental setup based on mathematical modeling and simulation displayed successful charging capabilities of MRC, with the alternate power source being the harvested RF energy. Mathematical formulae were applied to calculate the amount of power generated from the prototype circuit. LTSpice simulation software was applied to demonstrate the behavior of the different components in the circuit layout for effective WPT transfer.

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Research on Wireless Power Transmission Based on Magnetic Resonance Coupling

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.811.651 ◽

2013 ◽

Vol 811 ◽

pp. 651-656

Author(s):

Hao Wang ◽

An Na Wang ◽

Qiang Zhao ◽

Yu Zhang

Keyword(s):

Magnetic Field ◽

Magnetic Resonance ◽

Power Transmission ◽

Coupled Mode Theory ◽

Wireless Power ◽

Wireless Power Transmission ◽

Coupled Mode ◽

Magnetic Resonance Coupling ◽

Resonance Coupling ◽

Resonance Process

e. The formalism of wireless power transmission is discussed coupled mode theory can be used to describe the resonance process. According to the changing process of input impedance and input current to describe the demarcate of resonant frequency. also demonstrate that loop circuits have an important effect of the resonant magnetic field distribution.

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Power Delivery and Leakage Field Control Using an Adaptive Phased Array Wireless Power System

IEEE Transactions on Power Electronics ◽

10.1109/tpel.2015.2406673 ◽

2015 ◽

Vol 30 (11) ◽

pp. 6298-6309 ◽

Cited By ~ 44

Author(s):

Benjamin H. Waters ◽

Brody J. Mahoney ◽

Vaishnavi Ranganathan ◽

Joshua R. Smith

Keyword(s):

Power System ◽

Phased Array ◽

Power Delivery ◽

Wireless Power ◽

Leakage Field ◽

Field Control

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Spectroscopic imaging of human disease

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100166889 ◽

1996 ◽

Vol 54 ◽

pp. 884-885

Author(s):

D.J. Meyerhoff

Keyword(s):

Magnetic Field ◽

Magnetic Resonance ◽

Field Gradient ◽

Human Disease ◽

Morphological Changes ◽

Magnetic Field Gradient ◽

Spectroscopic Imaging ◽

Resonance Spectroscopy ◽

Tissue Water

Magnetic Resonance Imaging (MRI) observes tissue water in the presence of a magnetic field gradient to study morphological changes such as tissue volume loss and signal hyperintensities in human disease. These changes are mostly non-specific and do not appear to be correlated with the range of severity of a certain disease. In contrast, Magnetic Resonance Spectroscopy (MRS), which measures many different chemicals and tissue metabolites in the millimolar concentration range in the absence of a magnetic field gradient, has been shown to reveal characteristic metabolite patterns which are often correlated with the severity of a disease. In-vivo MRS studies are performed on widely available MRI scanners without any “sample preparation” or invasive procedures and are therefore widely used in clinical research. Hydrogen (H) MRS and MR Spectroscopic Imaging (MRSI, conceptionally a combination of MRI and MRS) measure N-acetylaspartate (a putative marker of neurons), creatine-containing metabolites (involved in energy processes in the cell), choline-containing metabolites (involved in membrane metabolism and, possibly, inflammatory processes),

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Nuclear magnetic resonance microscopy

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100156110 ◽

1989 ◽

Vol 47 ◽

pp. 828-829

Author(s):

Paul C. Lauterbur

Keyword(s):

Magnetic Field ◽

Nuclear Magnetic Resonance ◽

Magnetic Resonance ◽

Magnetic Fields ◽

Signal To Noise ◽

Field Gradients ◽

Useful Signal ◽

Magnetic Field Gradients ◽

Observation Times ◽

Nuclear Magnetic

Nuclear magnetic resonance imaging can reach microscopic resolution, as was noted many years ago, but the first serious attempt to explore the limits of the possibilities was made by Hedges. Resolution is ultimately limited under most circumstances by the signal-to-noise ratio, which is greater for small radio receiver coils, high magnetic fields and long observation times. The strongest signals in biological applications are obtained from water protons; for the usual magnetic fields used in NMR experiments (2-14 tesla), receiver coils of one to several millimeters in diameter, and observation times of a number of minutes, the volume resolution will be limited to a few hundred or thousand cubic micrometers. The proportions of voxels may be freely chosen within wide limits by varying the details of the imaging procedure. For isotropic resolution, therefore, objects of the order of (10μm) may be distinguished.Because the spatial coordinates are encoded by magnetic field gradients, the NMR resonance frequency differences, which determine the potential spatial resolution, may be made very large. As noted above, however, the corresponding volumes may become too small to give useful signal-to-noise ratios. In the presence of magnetic field gradients there will also be a loss of signal strength and resolution because molecular diffusion causes the coherence of the NMR signal to decay more rapidly than it otherwise would. This phenomenon is especially important in microscopic imaging.

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