Patent ID: 9647725
Date: 2017-05-09
CPC Classifications: H02J,H04B

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.