RFID Card Identification by Field Pause in Wireless Charging

The patent applies periodic action by pausing the RFID field at specific intervals during the communication protocol. The field is activated during initial communication to allow passive cards to respond, then paused before the final identification signal. This periodic on-off pattern creates distinguishable response behaviors: passive cards stop responding when the field is paused, while active cards continue to respond, enabling reliable type identification without compromising passive card functionality during active phases.

The patent applies preliminary action by performing all necessary identification steps during the initial communication phase while the RFID field is still active. The system exchanges commands and receives responses from both passive and active RFID cards before pausing the field. This preliminary identification ensures that passive cards are recognized and can be protected from damage in subsequent operations, while the pause still serves to confirm their passive nature through their cessation of responses.

The patent applies feedback by monitoring the response behavior of RFID cards to changes in field state. When the RFID field is paused, the system observes whether cards continue to send identification signals. Active cards provide continuous feedback signals even during the pause, while passive cards stop providing feedback. This feedback mechanism enables precise differentiation between card types while maintaining efficient detection of all RFID cards in the system.