Protection of an NFC or RFID radio system in the presence of strong electromagnetic fields

摘要

Methods and apparatus are described including a near field communication (NFC) or radio frequency identification (RFID) device having an NFC or RFID circuit, an antenna having at least a first port, a first rectifier connected to the first port of the Antenna is connected, a switch between the first rectifier and the NFC or RFID circuit, a voltage detector for detecting a voltage in the device, which is generated by a signal that is received at the antenna, and a control module for controlling the switch in which, when the voltage exceeds a threshold, the control module controls the switch to be in an open state and, after a predetermined period of time, determines whether the voltage still exceeds the threshold, and if the voltage is the predetermined one Size still exceeds, controls the switch so that it is in the open state det.