Patent ID: 11888550
Assignee: STMICROELECTRONICS (ROUSSET) SAS
Field: Telecommunications (Electrical engineering)
Classification: CPC H | IPC H

Claim 9:
10. A near field communications (NFC) receiver, comprising:
a first antenna tuned to an NFC communications frequency;
a second antenna tuned to a further frequency that is at least two times said NFC communications frequency;
wherein the first antenna and the second antenna are magnetically coupled with a coupling coefficient greater than 0.5;
a power receiving circuit electrically connected to the first antenna, but not the second antenna, where a resonant frequency of a circuit formed by the first antenna and the power receiving circuit is equal to the NFC communications frequency in a second operating phase for the NFC receiver to receive power for transfer to the power receiving circuit; and
an NFC data communications circuit electrically connected to the second antenna, but not the first antenna, where a resonant frequency of a circuit formed by the second antenna and the NFC data communications circuit is equal to the further frequency in the second operating phase and is equal to the NFC communications frequency in a first operating phase for the NFC receiver to receive data for transfer to the NFC data communications circuit;
wherein, in the first operating phase, the power receiving circuit is deactivated to produce an increased impedance of the power receiving circuit, the increase impedance causing, through the magnetic coupling of the first antenna and second antenna, an increase in an inductance of the second antenna so that the second antenna is configured to receive data transfer signals at the NFC communications frequency.