Single-Layer, Flexible, and Depolarizing Chipless RFID Tags

Radio Frequency Identification (RFID) is a modern wireless data transmission and reception technique for applications including automatic identification, asset tracking and security surveillance. As barcodes and other means of identification and asset tracking are inadequate for recent demands, RFID technology has attracted interest for applications such as logistics, supply chain management, asset tracking, and security access control. However, the cost of RFID limits their potential for the replacement of trillions of barcodes each year. The only possible solution is a fully printable chipless RFID tag. A novel RFID system comprised of a chipless RFID tag and an associated reader is reported in the thesis. The chipless tag is a fully-passive microwave circuit and uses spectral signatures for data encoding. The tag consists of a multi-resonator coupled to transmitting and receiving antennas. To accommodate multiple bits, the tag operates over the ultra wideband (UWB) frequency spectrum. UWB antennas are used to receive the interrogation signal sent from the reader and transmit the signal back to the reader after performing modulation of the frequency spectra with the multi-resonator. Modulation is performed in both amplitude and phase of the spectrum. A chipless tag up to 35 bits which operate over 3-7 GHz band has been designed. After the successful design of the chipless tag, three prototype readers have been developed. The Gen1 reader was designed to validate the chipless RFID concept using 6-bit chipless tag reading based on amplitude-only detection in S-band; the Gen2 reader is an upgraded version of Gen1 with both amplitude and phase detection capability; and the third generation reader is a UWB reader capable of reading up to 35-bits in the UWB band. The integrated reader is a complete system with analog RF and digital control sections loaded with graphical user interface (GUI) and software protocol. Both the hardware and software design of the RFID reader and field trials of the designed chipless RFID system have been validated in the real world environment. An investigation into antenna systems in order to enhance reading range up to 70 cm has also been performed. The unique features of the developed chipless RFID system are: (i) a low cost, fully printable tag and (ii) secure, remote and non-line-of-sight operability. The importance of this concept lies in the fact that chipless RFID tags become comparable to barcodes in terms of the substrate material used and the cost of fabrication. The main application of this chipless RFID system is in short-range tagging of extremely low cost items such as the Australian polymer banknote.

The letter presents the design, fabrication, and measurement of a configurable radio frequency identification (RFID) tag based on time‐domain reflections. The tag circuit contains a microstrip line (ML) that propagates radio frequency (RF) signals, and a group of capacitors that introduce impedance discontinuities to encode binary codes. The configurability of the tag circuit is allowed by connecting the nearby‐placed capacitors with the ML. Ink‐jet printing technology is employed to implement the layout of the proposed tag on paper substrate. To overcome the limitations of printed metallic tracks, a linearly tapering technique is proposed. With this technique, a four‐bit configurable passive chipless RFID tag is realized. Both time‐domain reflectometry (TDR) measurements and ultrawideband (UWB) characterizations were conducted for the proposed tag, and the results are in good consistence with the simulation ones from the circuit simulator advanced design system (ADS). Owing to its low cost fabrication and environmentally friendly nature, the proposed tag has great potential to be widely employed in low‐end RFID applications. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:2781–2786, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26412

Radio Frequency IDentification (RFID) technology successfully integrates radio transmitter and receiver, small size memory space and control circuitry to remotely store and retrieve data via wireless RF transceiver. As low-cost RFID tag can be massively manufactured by semiconductor industry, new applications associated with RFID technology have emerged rapidly such as inventory tracking, book storage and management, and airport baggage handling. Generally an RFID system is composed of many RFID tags (or tagged objects), at least one RFID reader, and one backend application system with database. An RFID tag gains its operation energy from query signals that are radio waves transmitted by RFID reader. Once a tag responds the query with its stored information to RFID reader, usually a unique identity number or string, the RFID system can recognize the tag carrier and perform required business logic operation. As RFID technique is widely used in supply chain management, the corresponding RFID application systems are expected to process and manage large amount of tagged objects at a predefined period of time regularly. Therefore, for large-scaled RFID applications, tag reading throughput is very critical since it will affect the total data processing time. To measure tag reading throughput of a RFID system, two performance criteria are usually adopted: tag reading delay and reader energy consumption [5]. As RFID reader and tag always communicate over a shared wireless channel, it is very easy to have signal collisions during a normal tag identification process when multiple tags exist in reader’s interrogation area. Signal collision results in query or data retransmission and eventually increases communication overhead and time delay of tag identification. Hence, an efficient tag collision arbitration mechanism is very important and critical for RFID systems to achieve effective performance. Existing RFID tag identification schemes can be classified into aloha-based solutions [3, 10, 12-13, 16, 21, 23-24] and tree-based solutions [1, 2, 4, 6-9, 14-15, 17-20, 22]. In aloha-based schemes, a reader estimates the number of tags in its interrogation area and broadcasts the total number of timeslots to each tag. Then each RFID tag randomly selects its own timeslot to transmit its ID without knowing which timeslots have been selected by other tags. By distributing tag responses to distinct timeslots instead of getting all tag responses at the same time, aloha-based schemes effectively reduce the probability of signal collision. However, aloha-based schemes have tag starvation problem in which certain tags may not

In this paper, a novel method of obstacle recognition and localization for mobile robots using radio frequency identification (RFID) technology and stereo vision is proposed as it is inexpensive, flexible and easy to use in practical environments. As information about the obstacles or environment can be written in ID tags, the proposed method can detect the obstacles easily and quickly compared with other methods. By considering the probabilistic uncertainty of RFID, we introduce Bayes rule to calculate probability where the ID tag exists. But the accuracy of localization of obstacles is not enough for mobile robot navigation just using one antenna. In this paper, we discuss using multi-antennas to localize obstacle with ID tags. After localizing ID tag, the stereo camera starts to process the image of the region of interest where the obstacle exists. The proposed method does not need to process all the image and easily gets some information about obstacles such as size, and color, and thus decreases the processing computation. This paper introduces the architecture of the proposed method and some experimental results.

Chipless radio frequency identification (RFID) is one of the major technology in real-time wireless applications. In this paper, an approach has been taken to generate a specific band for the communication of various wireless sensors. The proposed chipless RFID tag is designed for 3.5 GHz and 7.9 GHz frequency bands owing to obtain wireless communication in ultrawideband (UWB) frequency range. In this work, we focused to improve the magnitude of radar cross section (RCS) by using a modified Swastik-shaped geometry. The proposed tag has an overall dimension of 19× 16× 1.6mm2 and is found to be suitable for UWB applications.

In this paper, design requirements and advanced approaches for improved performance UHF radio frequency identification (RFID) tags are presented. Organic substrates are examined as highly potential candidates for RFID fabrications. An inkjet-printed tag on paper substrate is realized for ultra-low- cost mass production. RFID with sensor integration is also demonstrated for automotive sensing and vehicle security applications. Measurements are performed for RFID tags embedded in tires. These results show that proper designed RFID can serve for the purpose of tire pressure/temperature monitoring.

In this paper the impact of the signal bandwidth on the performance of frequency modulated continuous wave (FMCW) radar based ranging to ultra high frequency (UHF) radio frequency identification (RFID) tags is investigated. The analyses are based on ultra-wideband (UWB) channel measurements performed in a warehouse portal, which is a severe multipath environment. It is illustrated that the available bandwidth of the usual ISM bands at 900 MHz, 2.5 GHz and 5.8 GHz is only sufficient for a precise RFID tag localization if moderate or low multipath conditions are given. However, in severe multipath channels the ISM bands are unsuited and UWB signals are needed. The results can be considered a lower bound for signal time of flight (TOF) based localization approaches that utilize Fourier or correlation methods for the signal travel time estimation.

The paper focuses on the environmental burden created by Radio Frequency Identification (RFID) tags in the Slovak Republic (SR). In order to determine the burden there, a model example was created to calculate electronic waste produced by households in the SR by placing RFID tags into municipal waste. The paper presents a legislative regulatory approach towards the environmental impacts from using RFID tags in the SR, as well as an analysis of the environmental burden of using RFID tags throughout the world. The core of the paper is focused on the research conducted in order to calculate the environmental burden of a model household in the SR, where the number of used RFID tags per year was observed; then, the volume of e-waste produced by households of the Slovak Republic per year was determined. In the conclusion, we provide the results of the research presented and discuss including our own proposal for solving the problems connected with the environmental burden of RFID technology.

In the last decade, many articles have been pub­lished that demonstrate the susceptibility of cryptographic devices against implementation attacks. Usually, such devices draw their energy from a contact-based power supply. This power-supply connection is often exploited to extract the secret key by applying fault-injection methods and power-analysis attacks. In this article, we present implementation attacks on Radio Frequency Identification (RFID) tags which are usually powered contactlessly by an electromagnetic field. We describe a contact-based measurement setup that allows both injection of faults and measuring of the power consumption of passive RFID tags. Furthermore, we demonstrate the applicability of our setup by providing practical results of attacks on commercially available HF and UHF RFID tags. The results have led us to the conclusion that RFID tags are as susceptible to such attacks as contact-based powered devices. Appropriate countermeasures are needed to thwart these attacks.

Academicians and industry professionals have demonstrated the use of Radio Frequency Identification (RFID) Tags in construction applications in the past few years. Recently building information modelling (BIM) technology is emerging as the industry standard in the architecture, engineering and construction (AEC) sector. This paper combines the two technologies to monitor the movement of RFID tags in a BIM environment. Real-time monitoring of RFID tags in a building information model is an improvement over other methods of tracking construction workers, equipment and materials on the jobsite. Strategies for combining the two technologies are explored. This method of monitoring can be used to improve the safety and productivity of construction workers on a construction jobsite. This technique of monitoring RFID tags can also be used to track equipment and construction materials on a job-site. Autodesk Revit BIM software environment was used for tracking RFID tags. The paper includes discussion about the choice of RFID tags available for this method of tracking.

In this paper, we propose a novel tags identification protocol based on compressive sensing (CS) and ultra-wideband (UWB) for radio frequency identification (RFID) systems. In a hybrid RFID system, ultra-high-frequency (UHF) reader-to-tag communications are combined with the UWB transceivers for localization and ranging purposes. Here, the UWB information of such a hybrid UHF-UWB architecture is exploited to reduce the ID search space of a UHF-CS decoding scheme. Simulation results prove that our solution significantly decreases the amount of bits required for successful tags identification, compared with the state-of-the-art protocols.

In this paper, we focus on configuring a low cost RFID (Radio Frequency IDentification) system with less RFID readers and low density RFID tag textiles for stable and accurate self-localization for an omni-directional mobile robot. An RFID system using multiple RFID readers and high density RFID tags has already been applied to an indoor mobile robot self-localization. However, the system production cost is relatively high. To reduce the production cost of the system while maintaining the self-localization performance, we redesign two new RFID systems configured with 20 RFID readers and 5 RFID readers enlarging the size of an RFID reader antenna. Particularly, a new likelihood function of the tag detection with the redesigned large size RFID reader antenna is proposed for Monte Carlo Localization (MCL). Furthermore, we come up with a novel arrangement of RFID tags installed in a hexagon pattern. The new arrangement of ID tags enables both low cost ID tag installation and high performance of self-localization. We examine the performances of robot self-localization with less RFID readers and lower density RFID tags installed on the floor based on MCL(Monte Carlo localization). The simulation demonstrates the validity of our proposed configuration of the RFID based self-localization.

The detection of chipless radio frequency identification (RFID) tags is mostly realized by vector network analyzers. In actual detection, this method is expensive and not flexible enough. A flexible new detection method implemented on the Universal Software Radio Peripheral (USRP) is proposed in this article. The measurement object is a 6-bit chipless RFID coded tag sensor based on a spiral resonator trap circuit. The power detection function of the frequency band is designed and implemented on USRP's open-source platform GNU Radio. On this basis, for chipless RFID tags with spectrum coding, a decoding identification method based on maximum-likelihood estimation is designed. The frequency-domain curve of the scattered signal of the sample label is detected by the power detection method, and the decoding and identification test of the sample label is performed by the maximum-likelihood estimation decoding identification method. It is shown that the maximum-likelihood estimation decoding algorithm based on the USRP platform proposed can be effectively implemented in passive wireless networks through experimental results, which provides a new idea for the flexible and economical RFID tag detection method.

An 8-bit chipless radio-frequency identification (RFID) tag with a compact structure is proposed in this paper. Designing a RFID tag with a compact size is highly demanded in RFID technology. The original RFID tag is composed of 8 octagonal rings. In order to minimize its dimensions, the tag is divided in two equal parts. One part is completely omitted with its substrate. A grounded wall is placed in front of the remaining part to compensate the effects of the removed part and generate an image of it. Comparing a radar cross-section (RCS) of the compact and normal structure implies that by minimizing the tag, the RCS response of the structure is approximately similar with that of the normal tag. An equivalent circuit model for the RFID tag is presented, which shows a reasonable agreement with its full-wave result. The presented tag exhibits an RCS of σ = −26 dBsm from 2 to 7 GHz with an overall size of 15 × 30 mm2. Through using the aforementioned method, a 50% reduction in the overall area of the structure is observed.

In this paper, a novel method of obstacle recognition in indoor environment for mobile robot using RFID (Radio Frequency Identification) technology and stereo vision is proposed as it is inexpensive, flexible and easy to use in practical environment. Because information of the obstacles or environment can be written in ID tags, the proposed method can detect the obstacles easily and quickly compared with the other methods. The Radio Frequency is not so stable, so the Bayes rule was introduced to calculate probability where the ID tag exists in order to improve the accuracy of localizing obstacle with the ID tags. Then the stereo camera is started to process the image of ROI where the obstacle exists. The proposed method does not need to process all image and easily gets some information of obstacle such as size, color, thus decreases the processing computation. This paper introduces the architecture of the proposed method and presents some experimental results.