| 摘要 |
A method and apparatus for controlling a radio frequency identification (RFID) reader to detect the proximity of an RFID device based on observing a change in effective inductance. The RFID reader includes an excitation signal generator and a resonant filter that combined are capable of generating and transmitting a detection signal, an RFID device detector for measuring a detector parameter indicative of the change in effective inductance, and a detection signal receiver for determining whether an RFID device is present. The method includes awakening from a detection sleep state at a preselected time, generating and transmitting a detection signal, measuring at least one detector parameter indicative of the change in effective inductance, and determining whether the RFID device is present. When the RFID device is not present, the method returns to the detection sleep state and, when the RFID device is present, the method exits the detection sleep state.
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