The use of flare structures in increasing the performance of passive UHF RFID tags within metal pipes

In this paper, the utility of flare structures in metal pipes are introduced as a mechanism to increase the performance of passive UHF RFID tags operating within these metallic structures. These performance enhancements are noted to exist predominantly in the tag gain, which is a fundamental factor determining RFID tag readability. Theory is presented to describe in detail the design requirements of flares that can be used to enable the utility of passive UHF RFID tags within the FCC allowed band of 902 MHz to 928 MHz in the US for use in the track and trace of high valued metal pipes used in the oil and gas industry.