A Lightweight Segmented RFID Tag Antenna With a Combined Ferrite Core for Underground Applications

Current underground radio frequency identification (RFID) tags have not been able to meet the detection needs of pipeline burial toward deep areas. To effectively address this issue, in this work, a novel lightweight segmented RFID tag coil antenna with a combined ferrite core was presented. Based on the magnetic flux distributions of a traditional single large-sized ferrite core, multiple small ferrite cores were combined to replace the original single large core, and the arrangement and number of small ferrite cores were determined. Then, by analyzing the relationship between the coil winding mode and the antenna-distributed capacitance, a segmented winding skeleton was designed. To verify the proposed design, three different types of ferrite-core antennas were fabricated and measured. From the experimental results, the clear superiority of the proposed tag antenna, in terms of mass and working distance compared to the current traditional ferrite-core tag antenna, was demonstrated.