Design and development of novel radio frequency identification (RFID) tag structures

The objective of the proposed research is to design and develop a series of radio frequency identification (RFID) tag structures that exhibit good performance characteristics with cost optimization and can be realized on flexible substrates such as liquid crystal polymer (LCP), paper-based substrate and magnetic composite material for conformal applications. The demand for flexible RFID tags has recently increased tremendously due to the requirements of automatic identification in various areas. Several major challenges existing in today's RFID technologies need to be addressed before RFID can eventually march into everyone's daily life, such as how to design high performance tag antennas with effective impedance matching for passive RFID IC chips to optimize the power performance, how to fabricate ultra-low-cost RFID tags in order to facilitate mass production, how to integrate sensors with passive RFID tags for pervasive sensing applications, and how to realize battery-free active RFID tags in which changing battery is not longer needed. In this research, different RFID tag designs are realized on flexible substrates. The design techniques presented set the framework for answering these technical challenges for which, the focus will be on RFID tag structure design, characterization and optimization from the perspectives of both costs involved and technical constraints.Ph.D.Committee Chair: Tentzeris, Manos; Committee Member: DeJean, Gerald; Committee Member: Ingram, Mary; Committee Member: Kavadias, Stylianos; Committee Member: Laskar, Jo

Vehicle recognition system using RFID technology for parking management system

© Published under licence by IOP Publishing Ltd. Technology is growing each day by leaps and bounds. The change in technology has done wonders to increase productivity in everyday life. However, drivers searching for parking contributed to traffic congestion especially in urban and suburban cities, while consuming their time and energy. Besides, traffic congestion in parking area is always an issue which contribute to traffic on the main road. The current approach to overcome this includes the implementation of parking ticket system, especially in busy area. The hour rate for busy area is elevated to promote liquidation of vehicles. However, this system requires patrol warden to manually inspect each vehicle for the parking ticket. The feasibility of the system decreases when the parking area is larger. RFID parking management system aims to bring automation into parking system. The use of passive UHF RFID which can read multiple tags from long distance can replace patrol warden and thus increase the effectiveness of the Vehicle Parking Management System (VPMS). Furthermore, the power consumption of RFID system is analyzed. A new method has been introduced to reduce the power consumption of RFID system which operates 24/7. Experimental results demonstrate the effectiveness of the proposed method in reducing the power consumption of the RFID system

Evaluation of conductive threads for optimizing performance of embroidered RFID antennas

Radio frequency identification (RFID) refers to a technology that utilizes radio signals for identifying objects automatically. This technology consists of a reader that detects the objects and a transponder that gets attached to the object and it is called tag. The tag is an enclosure that houses the antenna and an IC that stores the necessary information on that object. This thesis focuses tag antennas made for embroidered RFID. Embroidered antennas are made by sewing antenna using conductive thread onto a fabric using a computerized sewing machine. This enables us to extend the field of RFID technologies to textiles. Conventional RFID systems that use metal conductors are easy to model but the same cannot be said for embroidered RFID. The reason being conductive threads and embroidered antennas don’t have definite conductivity. The conductivity of an embroidered antenna depends multiple factors like thread conductivity, thread density, stitch density, sewing pattern etc. The target of this thesis is experimenting with conductive threads physically and for their conductivity followed by eval-uating them for the use of embroidered RFID antenna fabrication for optimizing the perfor-mance. In this thesis, using same antenna pattern and technique, tags were fabricated from 6 differ-ent conductive threads onto the same cotton fabric. The conductive threads were investigated for their conductivity, thread thickness and their strength. The antennas were tested for their read range and the effect of different threads on the antenna were analysed. The threads with the highest conductive nature gave the highest read range of 6.2 meters. The threads were also evaluated for their usability for embroidery. Some threads were too thick, some had exposed structures leading to malfunction in the sewing machine and others were too thin and ripped easily during sewing. The selected thread should not only have great performance, but also it needs to be practical. It is seen that the conductivity of antenna and hence the performance is easily improved with using high conductive thread. After taking all the factors into account, finally a thread was selected that can be used to make high performance embroidered RFID antennas and also highly suitable for embroidery process. In the future, the same work can be revisited or extended to other more versatile and higher conductivity threads. Also, the advancement is embroidery techniques will allow for more con-ductive threads to be compatible for embroidery opening more options for optimization

A Dual Resonant Microstrip Antenna for UHF RFID in the Cold Chain Using Corrugated Fiberboard as a Substrate

Each year, about 76 million people contract a food borne illness in the United States; about 325,000 require hospitalization; and about 5,000 die. Tracking goods throughout the food supply chain increases the efficiency of recall of tainted goods and thus will help reducing food borne illness. Passive UHF RFID has been widely accepted to be a technology capable of increasing supply chain efficiency. Passive UHF RFID tags designed for supply chain application are tuned to work well on corrugated fiberboard boxes that are ubiquitous in the supply chain. Commercially available passive UHF RFID tags are either sensitive to the content/environmental conditions of the corrugated fiberboard box or economically unfeasible. In this thesis we propose a novel dual-resonant planar UHF RFID microstrip antenna designed to be both insensitive to the content/environmental conditions of the corrugated fiberboard box and economically feasible. We provide simulated performances and experimental validations to show that the proposed microstrip antenna design is a viable and technically superior solution compared to conventional stripline dipole antennas widely used in commodity tags

Target Read Operation of Passive Ultra High Frequency RFID Tag in a Multiple Tags Environment

Passive ultra-high frequency (UHF) radio frequency Identification (RFID) has emerged as a promising solution for many industrial applications. Passive UHF systems are relatively inexpensive to implement and monitor, as no line of sight is required for the communication. There are several advantages to using a passive RFID system. For example, no internal power source is required to activate the tags, and lower labor costs and efficient multitasking operations are expected in a long term scenario. However, due to factors such as tag-to-tag interference and inaccurate localization, RFID tags that are closely spaced together are difficult to detect and program accurately with unique identifiers. This thesis investigates two main ways to enable and improve multi-tag operations: physical tag placement and design of the near-field RFID reader antenna. First, several factors that affect the ability to encode a specific tag with unique information in the presence of other tags are investigated, such as reader power level, tag-to-antenna distance, tag-to-tag distance and tag orientation. A Full Factorial Design is carried out to study the effects of each of the factors and factor interactions. Results suggest a preliminary minimum tag-to-tag spacing which enables the maximum number of tagged items to be uniquely encoded without interference. In order to individually read each tag in a multi-tag form, an experimental device is built to enable controlled movement and positioning of the reader’s antenna to the location of each of the tags. The experimental device is also designed to test other mechanical means of isolating the tags, such as shielding and mechanical isolation of the tagged media. Furthermore, to test a second method of improving the efficacy of programming tags uniquely in a multi-tag environment, the reader’s antenna is redesigned to confine the electromagnetic field distribution to reduce the probability of activating non-targeted tags in the surrounding. Using the commercial software package ANSYS High Frequency Structural Solver (HFSS), the coupling interaction between the reader’s antenna and RFID tags was simulated to investigate the relative voltage induced in the target tag relative to each of the proximal tags. The new antenna is then fabricated and validated with the simulation results. With a better antenna design and ideals tag placement, the read operation of multiple tags can be improved and made more reliable. These findings can potentially expedite the process of field programming in item-level tagging and increase the throughput rate of unique tag encoding

ReLoc: Hybrid RSSI- and phase-based relative UHF-RFID tag localization with COTS devices

Radio frequency identification (RFID) technology brings tremendous advancements in the Industrial Internet of Things (IIoT), especially for smart inventory management, as it provides a fast and low-cost way of counting or positioning items in the warehouse. In the last decade, many novel solutions, including absolute and relative positioning methods, have been proposed for this application. However, the available methods are quite sensitive to the minor changes in the deployment scenario, including the orientation of the tag and antenna, the materials contained inside the carton, tag distortion, and multipath propagation. To this end, we propose a hybrid relative passive RFID localization method (ReLoc) based on both the received signal strength indicator (RSSI) and measured phases, which orders the RFID tags horizontally and vertically. In this article, the phase-based variant maximum likelihood estimation is proposed for lateral positioning, and the RSSI profiles of two tilted antennas are compared with each other for level distinguishing. We implement the proposed positioning system ReLoc with commercial off-the-shelf RFID devices. The experiment in a warehouse shows that ReLoc is a powerful solution for practical item-level inventory management. The experimental results show that ReLoc achieves an average lateral and level ordering accuracy of 94.6% and 94.3%, respectively. Notably, when considering liquid or metal materials inside the carton or tag distortion, ReLoc still performs excellently with more than 93% ordering accuracy both horizontally and vertically, indicating the robustness of the proposed method

Wireless sensor system for infrastructure health monitoring

In this thesis, radio frequency identification (RFID)-based wireless sensor system for infrastructure health monitoring (IHM) is designed and developed. It includes mountable semi-passive tag antenna integrated sensors capable of measuring critical responses of infrastructure such as dynamic acceleration and strain. Furthermore, the system is capable of measuring structural displacement. One of the most important parts of this system is the relatively small, tunable, construction material mountable RFID tag antenna. The tag antenna is electronically integrated with the sensors. Leading to the process of developing tag antenna integrated sensors having satisfactory wireless performance (sensitivity and read range) when mounted on concrete and metal structural members, the electromagnetic performance of the tag antenna is analyzed and optimized using both numerical and experimental procedures. Subsequently, it is shown that both the simulation and the experimental measurement results are in good agreement. The semi-passive RFID-based system is implemented in a wireless IHM system with multiple sensor points to measure dynamic acceleration and strain. The developed system can determine the natural frequencies of infrastructure and identify any state changes of infrastructure by measuring natural frequency shifts. Enhancement of the spectral bandwidth of the system has been performed under the constraints of the RFID hardware. The influence of the orientation and shape of the structural members on wireless power flow in the vicinity of those members is also investigated with the RFID reader-tag antenna system in both simulation and experiments. The antenna system simulations with a full-scale structural member have shown that both the orientation and the shape of the structural member influence the wireless power flow towards and in the vicinity of the member, respectively. The measurement results of the conducted laboratory experiments using the RFID antenna system in passive mode have shown good agreement with simulation results. Furthermore, the system’s ability to measure structural displacement is also investigated by conducting phase angle of arrival measurements. It is shown that the system in its passive mode is capable of measuring small structural displacements within a short wireless distance. The benchmarking of the developed system with independent, commercial, wired and wireless measurement systems has confirmed the ability of the RFID-based system to measure dynamic acceleration and strain. Furthermore, it has confirmed the system’s ability to determine the natural frequency of an infrastructure accurately. Therefore, the developed system with wireless sensors that do not consume battery power in data transmission and with the capability of dynamic response measurement is highly applicable in IHM

Analysis of Wireless Body-Centric Medical Sensors for Remote Healthcare

Aquesta tesi aborda el problema de trobar solucions confortables, de baixa potència i sense fils per aplicacions mèdiques. La tesi tracta els avantatges i les limitacions de tres tecnologies de comunicació diferents per la mesura de paràmetres del cos i mètodes per redissenyar sensors per avaluacions òptimes centrades en el cos. La tecnologia RFID es considera una de les solucions més influents per superar el problema del consum d'energia limitat, a causa de la presència de molts sensors connectats. També s'ha estudiat la tecnologia Bluetooth de baixa energia per resoldre els problemes de seguretat i la distància de lectura que, en general, representen el coll d'ampolla de RFID pels sensors de cos. Els dispositius analògics poden reduir dràsticament les necessitats d'energia a causa dels sensors i les comunicacions, considerant pocs elements i un mètode de transmissió simple. S'estudia un mètode de comunicació completament passiu, basat en FSS, que permet una distància de lectura raonable amb capacitats de detecció precises i confiables, que s'ha discutit en aquesta tesi. L'objectiu d'aquesta tesi és investigar múltiples tecnologies sense fils per dispositius portàtils per identificar solucions adequades per aplicacions particulars en el camp mèdic. El primer objectiu és demostrar la facilitat d'ús de les tecnologies econòmiques sense bateria com un indicador útil de paràmetres fisiopatològics mitjançant la investigació de les propietats de les etiquetes RFID. A més a més, s'ha abordat un aspecte més complex respecte a l'ús de petits components passius com sensors sense fils per trastorns del son. Per últim, un altre objectiu de la tesi és el desenvolupament d'un sistema completament autònom que utilitzi tecnologia BLE per obtenir propietats avançades mantenint baix tant el consum com el preuEsta tesis aborda el problema de encontrar soluciones confortables, inalámbricas y de baja potencia para aplicaciones médicas. La tesis discute las ventajas y limitaciones de tres tecnologías de comunicación diferentes para la medición en el cuerpo y los métodos para elegir y remodelar los sensores para evaluaciones óptimas centradas en el cuerpo. La tecnología RFID se considera una de las soluciones más influyentes para superar el consumo de energía limitado debido a la presencia de muchos sensores conectados. Además, la baja energía de Bluetooth se ha estudiado se ha estudiado la tecnologia Bluetooth de baja energia para resolver los problemas de seguridad y la distancia de lectura que, en general, representan el cuello de botella de la RFID para los sensores de cuerpo. Los dispositivos analógicos pueden reducir drásticamente las necesidades de energía debido a los sensores y las comunicaciones, considerando pocos elementos y un método de transmisión simple. Se estudia un método de comunicación completamente pasivo, basado en FSS, que permite una distancia de lectura razonable con capacidades de detección precisas y confiables, que se ha discutido en esta tesis. El objetivo de esta tesis es investigar múltiples tecnologías inalámbricas para dispositivos portátiles para identificar soluciones adecuadas para aplicaciones particulares en campos médicos. El primer objetivo es demostrar la facilidad de uso de las tecnologías económicas sin batería como un indicador útil de dichos parámetros fisiopatológicos mediante la investigación de las propiedades de las etiquetas RFID. Además, se ha abordado un aspecto más complejo con respecto al uso de pequeños componentes pasivos como sensores inalámbricos para enfermedades del sueño. Por último, un resultado de la tesis es desarrollar un sistema completamente autónomo que utilice la tecnología BLE para obtener propiedades avanzadas que mantengan la baja potencia y un precio bajo.This thesis addresses the problem of comfortable, low powered and, wireless solutions for specific body-worn sensing. The thesis discusses advantages and limitations of three different communication technologies for on body measurement and investigate methods to reshape sensors for optimum body-centric assessments. The RFID technology is considered one of the most influential solutions to overcome the limitated power consumption due to the presence of many sensors connected. Further, the Bluetooth low energy has been studied to solve security problems and reading distance that overall represent the bottleneck of the RFID for the body-worn sensors. Analog devices can drastically reduce the energy needs due to the sensors and the communications, considering few elements and a simple transmitting method. An entirely passive communication method, based on FSS is studied, enabling a reasonable reading distance with precise and reliable sensing capabilities, which has been discussed in this thesis. The objective of this thesis is to investigate multiple wireless technologies for wearable devices to identify suitable solutions for particular applications in medical fields. The first objective is to demonstrate the usability of the inexpensive battery-less technologies as a useful indicator of such a physio-pathological parameters by investigating the properties of the RFID tags. Furthermore, a more complex aspect regards the use of small passive components as wireless sensors for sleep diseases has been addressed. Lastly, an outcome of the thesis is to develop an entirely autonomous system using the BLE technology to obtain advanced properties keeping low power and a low price