| 摘要 |
<p>An RFID security tag (20, 120, 220, 320, 420) which changes its reflectivity- after receiving an interrogation signal is provided. The RFID security tag (20, 120, 220, 320, 420) changes its reflectivity so that it becomes transparent to RF power of the RFID reader interrogation signal (204) once the RFID security tag responds, thereby permitting surrounding RFID security tags to absorb the interrogation signal (204) and to respond thereto. These surrounding RFID security tags then, in turn, change their reflectivity so that RFID security tags surrounding that second set of RFID security tags can absorb the interrogation signal (204) and can also respond thereto. In this manner, a large plurality of RFID security tags, such as those associated with merchandise loaded on a palette, can be interrogated accurately.</p> |
