Wireless power interface using an NFC antenna
First Claim
1. A circuit comprising:
- an antenna;
a first port coupled to the antenna using a first reactive circuit, the first port including first and second input nodes;
a first switching device coupled across the first and second input nodes of the first port and configured to convey a signal across the first and second input nodes to a Near Field Communication (NFC) circuit in a first mode, wherein the antenna has a resonance at a first frequency, and to isolate the NFC circuit from the antenna in a second mode;
a second port coupled to the antenna using a second reactive circuit, the second port including first and second input nodes;
a rectifier having an input coupled to the second port and an output coupled to an energy storage device; and
a second switching device configured to control an amount of current flowing through the rectifier, the second switching device being connected across the first and second input nodes of the second port,wherein when the circuit is in a second mode, the antenna is tuned to have a second resonance at a second frequency and the second switching device alternates between a first state and a second state at a third frequency equal to or higher than the second frequency.
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Accused Products
Abstract
A circuit comprises an antenna and a first port coupled to the antenna using a first reactive circuit. A first switching device is coupled across first and second input nodes of the first port, and configured to convey a signal across the first and second input nodes to a Near Field Communication (NFC) circuit in a first mode, and to isolate the NFC circuit from the antenna in a second mode. The antenna has a first resonance at a first frequency in a first mode and has a second resonance at a second frequency in a second mode. A second port is coupled to the antenna using a second reactive circuit. A rectifier has an input coupled to the second port and an output coupled to an energy storage device. A second switching device is coupled across the second port and configured to control an amount of current flowing through the rectifier by alternating between a first state and a second state at a third frequency when the circuit is in the second mode.
13 Citations
10 Claims
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1. A circuit comprising:
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an antenna; a first port coupled to the antenna using a first reactive circuit, the first port including first and second input nodes; a first switching device coupled across the first and second input nodes of the first port and configured to convey a signal across the first and second input nodes to a Near Field Communication (NFC) circuit in a first mode, wherein the antenna has a resonance at a first frequency, and to isolate the NFC circuit from the antenna in a second mode; a second port coupled to the antenna using a second reactive circuit, the second port including first and second input nodes; a rectifier having an input coupled to the second port and an output coupled to an energy storage device; and a second switching device configured to control an amount of current flowing through the rectifier, the second switching device being connected across the first and second input nodes of the second port, wherein when the circuit is in a second mode, the antenna is tuned to have a second resonance at a second frequency and the second switching device alternates between a first state and a second state at a third frequency equal to or higher than the second frequency. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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Specification