UHF RFID tag sensitive to object material

A UHF passive RFID tag being sensitive to dielectric property of object to be identified is designed and tested. The proposed RFID tag operates at 915MHz and has dimensions of 35mm×17.5mm(0.11λ*0.06λ)· The tag is designed to be very admissive of paper-like objective of relative dielectric constant of 2.5. When attached to objectives of other dielectric constants, the operation range of the tag degrades significantly, which indicates a tag can be bound up with objects of specific material.