System and method for selective transfer of radio frequency power
First Claim
1. A system comprising:
- a first unit with a substantially flat top surface, operatively connectable to a RF power source having at least a first frequency, and including an array of local resonance circuits having a resonance frequency selected to present a large load impedance to the RF power source; and
a secondary unit, including a resonance circuit having an adaptive self impedance such that when the secondary unit couples to a local resonance circuit, the local resonance circuit presents a lower load impedance to the RF power source allowing radio frequency power to flow from the first unit to the secondary unit.
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Accused Products
Abstract
A system and method is provided for the inductive transfer of electric power between a substantially flat primary surface and a multitude of secondary devices in such a way that the power transfer is localized to the vicinities of individual device coils. The contact free power transfer does not require precise physical alignment between the primary surface and the secondary device and can allow the secondary device or devices to be placed anywhere and in arbitrary orientation with respect to the primary surface. Such power transfer is realized without the need of complex high frequency power switching network to turn the individual primary coils on or off and is completely scalable to almost arbitrary size. The local anti-resonance architecture of the primary device will block primary current from flowing when no secondary device or devices are in proximity to the local RF power network. The presence of a tuned secondary device detunes the local anti-resonance on the primary surface; thereby enable the RF power to be transferred from the local primary coils to the secondary device. The uniformity of the inductive coupling between the active primary surface and the secondary devices is improved with a novel multi-pole driving technique which produces an apparent traveling wave pattern across the primary surface.
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Citations
25 Claims
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1. A system comprising:
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a first unit with a substantially flat top surface, operatively connectable to a RF power source having at least a first frequency, and including an array of local resonance circuits having a resonance frequency selected to present a large load impedance to the RF power source; and a secondary unit, including a resonance circuit having an adaptive self impedance such that when the secondary unit couples to a local resonance circuit, the local resonance circuit presents a lower load impedance to the RF power source allowing radio frequency power to flow from the first unit to the secondary unit. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17)
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18. A method of transferring power from a first unit including local resonant circuits having a large load impedance at a first frequency, to a secondary unit that includes a resonant circuit having a self impedance, comprising:
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supplying radio frequency voltages to the local resonant circuits in the first unit; adjusting the self impedance of the secondary unit in response to the secondary unit being proximate to at least one of the local resonant circuits in the first unit; and transferring power from the first unit to the secondary unit via the at least one of the local resonant circuits and the resonant circuit of the secondary unit. - View Dependent Claims (19, 20, 21, 22, 23, 24, 25)
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Specification