Capacitive shield for containing radiofrequency magnetic fields
First Claim
1. An RF magnetic shield for use in a radiofrequency system including an RF magnetic field resonator for generating an RF magnetic field having a magnetic component and an electric component, the RF magnetic shield comprising:
- a dielectric layer having a plurality of conductive regions separated by non-conductive regions on each side of the dielectric layer, the conductive regions overlapping on opposite sides of the dielectric layer to form a plurality capacitive elements which are partially non-conductive at radio frequencies such that the electrical component tangent to the shield is other than zero and the magnetic component perpendicular to the shield is essentially zero.
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Accused Products
Abstract
RF magnetic shields which support tangential electric fields. The RF shields are particularly suited for use in magnetic resonance imaging (MRI) systems, but may also be used in other radio frequency applications. The RF magnetic shields may include a dielectric layer having conductive regions separated by non-conductive regions on each side thereof to form a plurality of capacitive elements. The capacitive elements are partially non-conductive at radio frequencies such that the electrical component tangent to the shield is supported and the magnetic component perpendicular to the shield is blocked. The size and shape of the non-conductive and conductive regions are selected to develop a capacitive voltage across the capacitive elements at radio frequencies, and be substantially non-conductive at frequencies other than RF. The RF magnetic shields provide an electrical field that is uniform around the entire sample volume.
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Citations
25 Claims
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1. An RF magnetic shield for use in a radiofrequency system including an RF magnetic field resonator for generating an RF magnetic field having a magnetic component and an electric component, the RF magnetic shield comprising:
- a dielectric layer having a plurality of conductive regions separated by non-conductive regions on each side of the dielectric layer, the conductive regions overlapping on opposite sides of the dielectric layer to form a plurality capacitive elements which are partially non-conductive at radio frequencies such that the electrical component tangent to the shield is other than zero and the magnetic component perpendicular to the shield is essentially zero.
- View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19)
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20. A magnetic resonance imaging (MRI) system, comprising:
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an RF magnetic field coil for generating an RF magnetic field having a magnetic component and an electric component; and
an RF magnetic shield disposed adjacent the RF magnetic field coil, the RF magnetic shield being partially non-conductive at radio frequencies such that the average electrical component tangent to the shield is other than zero and the magnetic component perpendicular to the shield is essentially zero. - View Dependent Claims (21, 22, 23, 24, 25)
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Specification