Analysis of Composite Structure Effect on Radio-Frequency Characteristics of the RFID Tag

Radio-frequency identification (RFID) is the wireless use of electromagnetic fields to transfer data, for the purposes of automatically identifying and tracking tags attached to objects. Depending on the type of the material being tracked, the radio-frequency characteristics of the RFID tag may be very different. This paper aims to investigate how the RFID tag readability changes, when tags are attached to the composite structures. For this purpose, a number of different composite materials – based on carbon fibres, linen fibres and fibreglass, were selected and tested, in order to investigate their effect on radio-frequency characteristics of the RFID tag. For the purpose of this experiment passive tags have been used, which works by reflecting the RFID signal sent by the antenna. Such measurement settings allow us to assess the RF attenuation/amplification characteristics of tested materials and eliminate any other measurement errors such as those associated with the power and battery capacity of an active tag. The experimental results show that depending on the types of fibres used, the composite materials can either be used to attenuate or strengthen tag’s radio signal reflection characteristic measured by received signal strength indicator (RSSI) on the RFID reader.