A Comparative Survey on Silicon Based and Surface Acoustic Wave (SAW)-Based RFID Tags: Potentials, Challenges, and Future Directions

Abstract

Many Automatic Identification (Auto-ID) technologies such as bar codes, magnetic stripes, Optical Character Recognition (OCR) and Electronic Article Surveillance (EAS) security tags are in existence. However, they are limited by a variety of constraints on them such as limited object rate of scan, need for Line-of-Sight (LOS) operation, very small interrogation range and poor accuracy in complex environments. Research has accordingly grown rapidly in recent years into the development of robust identification or tracking mechanisms. Radio Frequency Identification (RFID) technology using readers and RFID tags, whether passive, semi-passive or active in nature, has been deemed to be a promising candidate. Silicon based IC tags are quite popular. However, some alternative RFID technologies have also been on the rise. In particular, another special type of tag based on Surface Acoustic Wave (SAW) design also has a great potential for deployment in future identification fields due to its ruggedness against harsh conditions, metallic environments, interference, small and low cost and is being thoroughly reviewed, which is ignored in other survey papers. While other chipless RFID systems based on conductive ink, ink-tattoo and others do exist, negative aspects such as inability to survive in extreme weather, larger tag size and limited data storage capacity have severely impacted the penetration of such tags in the RFID market. Therefore, the scope of this survey article does not include chipless RFID tags. This article instead provides a comparative survey of silicon based IC and SAW based tags, which has attracted much attention from both academia and industry. The underlying characteristics, principles, advantages, and limitations of such tags are thoroughly discussed, and relevant research work followed by frequency of operation and other parameters are elaborated. This article undertakes a thorough investigation into the evolution of RFID technology and comparison into the current trend in silicon based IC and SAW based RFID tags and provides a comparison across many metrics, such as read range, tag size, tag power, availability of tag power, lifespan and more importantly, cost and security. It discusses active and passive tags under silicon based IC and SAW technology. Finally, the article reviews recent advances and provides potentials, open challenges and future research directions in such RFID tags. INDEX TERMS RFID tracking/identification, surface acoustic wave (SAW), interdigital transducer (IDT), silicon based integrated circuit (IC) RFID tags, near field, far field communication. 2) ELECTROMAGNETIC BACKSCATTER/FAR FIELD RFID COMMUNICATION

Simultaneous Detection of Multiple Surface Acoustic Wave Sensor Tags for Water Quality Monitoring Utilizing Cellular Code-Reuse Approach

“…However, loading the inductor across the reflecting IDT requires an additional work during the fabrication process which also increases the overall cost per SAW tag. But this additional increase in cost can be reduced or even further through the use of silicon based multilayer substrates or Polyvinylidene fluoride (PVDF) [44], [45] in conjunction with an appropriate choice of fabrication technique. Thus, the components such as the antenna and the inductor for resonant loading can be built and integrated with reflecting IDTs on the same low-cost substrate which reduces the cost per SAW tag and as a bulk.…”

RFID Sensors for Monitoring Glazing Units Integrating Photovoltaic Modules

“…These functions can be performed without the participation of the supervising system and provide, to some extent, autonomy of the tag. A comprehensive survey on the RFID technology and its contemporary applications is given in [24].…”

A Low-Power Passive UHF Tag With High-Precision Temperature Sensor for Human Body Application

“…TCVTH and TC1 are negative temperature coefficients, ΔT = T-T0. Formulas ( 21) and ( 22) are replaced into formula (23). Current I can be expressed as a function of temperature T and expanded by Taylor series as follows:…”

“…Nowadays, the use of RFID in various applications such as supply chain management [10], public transportation [11]- [13], and access control [14] has become an unstoppable trend [15]. Recently, the combination of RFID and sensing systems have expanded the application of RFID to environmental monitoring [16]- [23] and healthcare [24]- [25]. For example, the sensors mentioned in the work of Shafiq et al and Camera et al [26]- [27] are generally designed for temperature measurement.…”