Wireless power multi-coil mutual induction cancellation methods and apparatus
First Claim
1. A device configured to transmit wireless power to a first receiver, comprising:
- a first driver coil;
a second driver coil;
a third driver coil; and
a circuit operably coupled to the first driver coil, the second driver coil, and the third driver coil and configured to at least partially cancel mutual inductance between the first driver coil, the second driver coil, and the third driver coil, the first, second, and third driver coils configured to share a common ground via the circuit,wherein each of the first, second, and third driver coils are driven by a corresponding first power amplifier, second power amplifier, and third power amplifier, respectively, and wherein each of the first, second, and third power amplifiers are driven out of phase of each other.
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Accused Products
Abstract
This invention describes a method and apparatus to cancel the mutual inductance between mutually coupled transmit coils, each of the transmit coils fed by individual power amplifiers, and the transmit coils all sharing a common ground with the power amplifiers. The methods and systems disclosed consist of coupling the return legs of each transmit coil to a mutual inductance cancellation circuit near a common ground return connection. The cancellation circuit uses a combination of inductors and capacitors to bridge various combinations of the transmit coils without physically connecting the “bridged” transmit coils. Transmit coils “bridged” using inductors have positive mutual inductance added to them, while transmit coils “bridged” using capacitors have negative mutual inductance added to them. Additionally, manipulation of the transmit coil overlap of overlapping transmit coils and/or manipulation of the location of the cancellation circuit can be used finely tune the mutual inductance between the transmit coils.
27 Citations
31 Claims
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1. A device configured to transmit wireless power to a first receiver, comprising:
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a first driver coil; a second driver coil; a third driver coil; and a circuit operably coupled to the first driver coil, the second driver coil, and the third driver coil and configured to at least partially cancel mutual inductance between the first driver coil, the second driver coil, and the third driver coil, the first, second, and third driver coils configured to share a common ground via the circuit, wherein each of the first, second, and third driver coils are driven by a corresponding first power amplifier, second power amplifier, and third power amplifier, respectively, and wherein each of the first, second, and third power amplifiers are driven out of phase of each other. - View Dependent Claims (2, 3, 4, 5, 7, 9, 10, 11, 12, 13, 14)
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6. A device configured to transmit wireless power to a first receiver, comprising:
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a first driver coil; a second driver coil; a third driver coil; and a circuit operably coupled to the first driver coil, the second driver coil, and the third driver coil and configured to at least partially cancel mutual inductance between the first driver coil, the second driver coil, and the third driver coil, the first, second, and third driver coils configured to share a common ground via the circuit, wherein the circuit comprises a capacitor configured to add negative mutual inductance to one or more coupled driver coils. - View Dependent Claims (22, 23, 24, 25, 26)
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8. A device configured to transmit wireless power to a first receiver, comprising:
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a first driver coil; a second driver coil; a third driver coil; and a circuit operably coupled to the first driver coil, the second driver coil, and the third driver coil and configured to at least partially cancel mutual inductance between the first driver coil, the second driver coil, and the third driver coil, the first, second, and third driver coils configured to share a common ground via the circuit, wherein the circuit comprises an inductor configured to add positive mutual inductance to one or more coupled driver coils. - View Dependent Claims (27, 28, 29, 30, 31)
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15. A method for transmitting wireless power to a receiver, comprising:
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generating, via a first driver coil, a first wireless field; generating, via a second driver coil, a second wireless field; generating, via a third driver coil, a third wireless field; canceling, via a cancellation circuit operably coupled to the first driver coil, the second driver coil, and the third driver coil and configured to at least partially cancel mutual inductance between the first driver coil, the second driver coil, and the third driver coil, at least a portion of a mutual inductance caused by at least one of the first wireless field, the second wireless field, and the third wireless field; and driving each of the first, second, and third driver coils with a corresponding first power amplifier, second power amplifier, and third power amplifier, respectively, wherein each of the first, second, and third power amplifiers are driven out of phase with each other. - View Dependent Claims (16, 17, 18, 19)
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20. A device configured to transmit wireless power to a first receiver, comprising:
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means for generating a first wireless field; means for generating a second wireless field; means for generating a third wireless field; means for canceling mutual inductance operably coupled to the means for generating the first wireless field, the means for generating the second wireless field, and the means for generating the third wireless field and configured to at least partially cancel mutual inductance between the means for generating the first wireless field, the means for generating the second wireless field generating means, and the means for generating the third wireless field, the means for generating the first wireless field, the means for generating the second wireless field, and the means for generating the third wireless field each configured to share a common ground via the mutual inductance canceling means; means for driving the means for generating the first wireless field; means for driving the means for generating the second wireless field; and means for driving the means for generating the third wireless field, wherein each of the means for driving the means for generating the first wireless field, the means for driving the means for generating the second wireless field, and the means for driving the means for generating the third wireless field are driven out of phase with each other. - View Dependent Claims (21)
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Specification