Characterization of passive UHF RFID tags in toroidal metal pipes

Abstract

Recently, automated identification techniques that utilize radio frequency (RF) systems have experienced growth both in the industry and in research worldwide. The current state-of-art of this identification realm is the radio frequency identification (RFID) system, which utilizes a transponder with a unique identifier. RFID systems can be classified into active systems (with built-in power supply), passive systems (requires RF energy scavenging), and other semi-active and semi-passive systems [1]. The utilization of passive RFID systems have experienced a tremendous growth in the last decade, specifically in the supply chain area due to its' ability to offer process automation at a low price point, thus enabling return-on-investments (ROI) for corporations worldwide. In an attempt to derive an effective solution to their supply chain needs, many industries such as the oil and gas industry has since invested on research to understand the limitations of this passive (tag) technology. Unlike most other industries, the pipeline and tubular industry has a unique problem that requires the use of passive RFID tags inside metal pipes. These tags are typically required to be placed inside these metallic structures due to the stacking problems inherent in the storage facility of these large pipes. There has been much research focusing on the characteristics of these passive tags and systems within the metal pipe [2–7], however these studies have not previously focused extensively on passive UHF RFID tags operating in toroidal metal pipes. Toroidal metal pipes are often used as interconnects for the longer cylindrical metal pipes as studied in [2, 3], and present more irregularities (radial ratios must be studied independently from curvature) than studied in [8].