RFID TAG, AND SYSTEM AND METHOD FOR DETECTING CHANGE OF RFID TAG ENVIRONMENT

摘要

Provided is an RFID tag suitable for detecting a change of the RFID tag environment in real time by a simple and low-cost system. The system and the method for detecting a change of the RFID tag environment are also provided. An RFID tag (2) is provided with an antenna (20), a wireless communication IC (21) for transmitting/receiving radio waves through the antenna (20), and an element (22A) of which characteristics change corresponding to a change of the physical quantity of the RFID tag environment. Gain of the antenna (20) changes due to a change of the characteristics of the element (22A). When the environment of the RFID tag (2) changes, gain of the antenna (20) is reduced or increased by the element (22A). Thus, the RFID tag (2) is brought into a state where answering waves (ANS) to interrogation waves (RQ) transmitted from a tag communication device (3) can be transmitted and into a state where such waves cannot be transmitted, and the change of the environment of the RFID tag (2) can be detected in real time, depending on whether the answering waves (ANS) are received or not.