摘要 |
Methods and devices are described, including a near-field communications (NFC) or radio frequency identification (RFID) device comprising an NFC or RFID circuit, an antenna having at least a first terminal, a first rectifier connected to the first terminal of the antenna, a switch between the first rectifier and the NFC or RFID circuit, a voltage detector for detecting a voltage in the device caused by a signal received at the antenna, and a control module for controlling the switch, wherein when the voltage exceeds a threshold magnitude, the control module controls the switch to be in an open state and, after a predetermined time period, determines whether the voltage still exceeds the threshold magnitude and, if the voltage still exceeds the predetermined magnitude, controls the switch to be in the open state. |