Tunable resonant inductive coil systems for wireless power transfer and near field communications
First Claim
1. A tunable resonant inductive coil system, comprising:
- an electrical circuit comprising an alternating current (AC) voltage source, a single barium strontium titanate (BST) tunable capacitor coupled in series with a first terminal of the AC voltage source, a coil coupled in series with the single BST tunable capacitor, and a return line coupling the coil with one of a second terminal of the AC voltage source and a ground;
wherein the electrical circuit forms an LC circuit (resonant circuit);
wherein the electrical circuit is configured to, in response to receiving one or more electrical signals, adjust between a first configuration and a second configuration, wherein in the first configuration the resonant circuit has a first resonant frequency configured to be used for wireless power transfer and in the second configuration the resonant circuit has a second resonant frequency configured to be used for near field communication (NFC), wherein an entire length of the coil is used for both the first resonant frequency and the second resonant frequency, and;
wherein adjusting the electrical circuit between the first configuration and the second configuration comprises varying a capacitance of the single BST tunable capacitor in response to receiving a control signal at the single BST tunable capacitor.
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Accused Products
Abstract
A tunable resonant inductive coil system includes an electrical circuit having an alternating current (AC) voltage source, a barium strontium titanate (BST) variable capacitor coupled in series with a first terminal of the AC voltage source, a coil coupled in series with the BST variable capacitor, and a return line coupling the coil with a second terminal of the AC voltage source and/or a ground. The electrical circuit forms an LC circuit (resonant circuit). The electrical circuit adjusts between two configurations. In the first configuration the resonant circuit has a first resonant frequency configured for wireless power transfer and in the second configuration it has a second resonant frequency configured for near field communication (NFC). An entire length of the coil is used for both resonant frequencies. Adjusting between the first and second configurations includes varying a capacitance of the BST variable capacitor in response to receiving a control signal.
22 Citations
16 Claims
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1. A tunable resonant inductive coil system, comprising:
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an electrical circuit comprising an alternating current (AC) voltage source, a single barium strontium titanate (BST) tunable capacitor coupled in series with a first terminal of the AC voltage source, a coil coupled in series with the single BST tunable capacitor, and a return line coupling the coil with one of a second terminal of the AC voltage source and a ground; wherein the electrical circuit forms an LC circuit (resonant circuit); wherein the electrical circuit is configured to, in response to receiving one or more electrical signals, adjust between a first configuration and a second configuration, wherein in the first configuration the resonant circuit has a first resonant frequency configured to be used for wireless power transfer and in the second configuration the resonant circuit has a second resonant frequency configured to be used for near field communication (NFC), wherein an entire length of the coil is used for both the first resonant frequency and the second resonant frequency, and; wherein adjusting the electrical circuit between the first configuration and the second configuration comprises varying a capacitance of the single BST tunable capacitor in response to receiving a control signal at the single BST tunable capacitor. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A tunable resonant inductive coil system, consisting of:
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an electrical circuit consisting of an alternating current (AC) voltage source; a single barium strontium titanate (BST) tunable capacitor, the single BST tunable capacitors coupled in series with a first terminal of the AC voltage source; a control element configured to control the capacitance of the single BST tunable capacitor; a coil coupled in series with the first terminal of the AC voltage source; a return line coupling the coil with one of a second terminal of the AC voltage source and a ground; a switch coupled with the AC voltage source; a direct current (DC) voltage source controlling the switch, and; one or more additional passive electrical components; wherein the electrical circuit forms an LC circuit (resonant circuit); wherein the electrical circuit is configured to, in response to receiving one or more electrical signals, adjust between a first configuration and a second configuration by one of opening and closing the switch and by correspondingly varying a capacitance of the single BST tunable capacitor, wherein in the first configuration the resonant circuit has a first resonant frequency configured to be used for wireless power transfer and in the second configuration the resonant circuit has a second resonant frequency configured to be used for near field communication (NFC), and; wherein an entire length of the coil is used for both the first resonant frequency and the second resonant frequency.
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9. A method of use of a tunable resonant inductive coil system, comprising:
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providing an electrical circuit, the electrical circuit comprising an alternating current (AC) voltage source having a first terminal, a single barium strontium titanate (BST) tunable capacitor electrically coupled in series with the first terminal of the AC voltage source, a coil electrically coupled in series with the single BST tunable capacitor, and a return line electrically coupling the coil with one of a second terminal of the AC voltage source and a ground; in response to the electrical circuit receiving a control signal at the single BST tunable capacitor, adjusting a capacitance of the single BST tunable capacitor to adjust a resonant frequency between a first resonant frequency configured to be used for wireless power transfer and a second resonant frequency configured to be used for near field communication (NFC), and; using an entire length of the coil for both the first resonant frequency and the second resonant frequency. - View Dependent Claims (10, 11, 12, 13, 14, 15, 16)
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Specification