SPACE COMPLEX PERMITTIVITY VARIATION DETECTION DEVICE AND ITEM AVAILABILITY DETECTION SYSTEM

摘要

Provided are a device detecting a spatial variation of a complex permittivity and an system detecting presence/absence of an article which are capable of detecting the presence or absence of an article by using a UHF-band RFID tag. A device detecting a spatial variation of a complex permittivity (10) includes an RFID tag (101), a conductor electrode unit (105), and a dielectric tag base material (104). The RFID tag (101) performs communication using an electromagnetic wave in a UHF band. The conductor electrode unit (105) communicates with the RFID tag (101) by using the electromagnetic wave in the UHF band. The dielectric tag base material (104) is provided between the RFID tag (101) and the conductor electrode unit (105) and separates the RFID tag (101) from the electrode unit (105).