NFC OR RFID DEVICE RF DETUNING DETECTION AND DRIVER OUTPUT POWER REGULATION

摘要

A near field communication (NFC) or Radio Frequency Identification (RFID) reader device for contact-less communication includes a transmitter block connected to an antenna via a matching circuitry. An electromagnetic carrier signal and modulated data information are emitted via this main antenna. Any secondary object brought into the vicinity of the main antenna influences the primary resonant circuit resulting in a load change seen by the transmitter. This detuning can cause increased power consumption, RF (Radio Frequency) standard incompliance, and device damage. The present disclosure describes devices and methods on how to detect detuning and how to regulate the transmitter's output.

主权项

1. A method for detuning detection and transmitter (TX) current regulation, the method comprising:
monitoring, by a sensor within a transmitter, a transmitter (TX) current and/or voltage; detecting a detuning of an antenna and matching network by a change in the TX current and/or voltage; in response to detection of the detuning, regulating the TX current.