High Performance UHF RFID Tags for Item-Level Tracing Systems in Critical Supply Chains

The need of a traceability system implemented at item level is becoming more and more essential in many business processes and, among the different potential enabling technologies, passive Radio Frequency Identification (RFID) (Finkenzeller, 2003) is undeniably the most adequate candidate. Indeed, its simplicity of use as well as its very attractive cost-benefit ratio, give a strong appeal to RFID. Among the many application sectors, the pharmaceutical supply chain, with millions of medicines moving around the world and needing to be traced at item level, represents a very interesting test-case. Furthermore, the growing counterfeiting problem raises a significant threat within the supply chain system. Moreover, several international institutions (e.g. Food and Drug Administration, European Medicines Agency, European Federation of Pharmaceutical Industries and Associations) are encouraging the use of innovative solutions in healthcare and pharmaceutics, to improve patient safety and enhance the efficiency of the pharmaceutical supply chain. In order to select the most adequate hardware solution, though, several aspects must be compulsory taken into account, including the working frequency, the near or far field empowering methods, but also the differences among the various RFID-based checkpoints of a generic supply chain (De Blasi et al., 2009; Uysal et al., 2008). The choice between the two main RFID solutions, High Frequency (HF) or Ultra High Frequency (UHF), can be aided by several recent works, which highlight how passive UHF RFID systems provide better performance than passive HF ones, see for example (Uysal et al., 2008). Hence, UHF seems to be the most promising technology for item-level traceability on the whole supply chain. The success of UHF can be mainly attributed to the assertion of the EPCglobal (Thiesse et al., 2009) international standard. Furthermore, UHF has several advantages over HF and LF technologies: the capability to enable multiple simultaneous readings of tags, the capacity to offer very high read rates, in addition to the much longer reading distance. Unfortunately, performance of UHF systems depends on several parameters (Bertocco et al., 2009), which are strongly related to environment, design and setup choices. For example, it is well known that a supply chain is composed of several steps that have different