Advanced Radio Frequency Identification Design and Applications

Radio Frequency Identification (RFID) is a modern wireless data transmission and reception technique for applications including automatic identification, asset tracking and security surveillance. This book focuses on the advances in RFID tag antenna and ASIC design, novel chipless RFID tag design, security protocol enhancements along with some novel applications of RFID

Performance Analysis of Effective Range and Orientation of UHF Passive RFID

The purpose of this research is to characterize the performance of UHF passive RFID tags. Factors of importance are the impact of tag orientation and distance from the RFID reader. Within this study, a comprehensive literature review of RFID technology is presented as well as the methodology used for the research. Furthermore, an analysis of RFID tag experiments is discussed and the results reviewed. To accomplish this task, two main objectives have been established as goals for the study. The first objective is to determine an optimum tag orientation within the RFID reader’s normal read range. Once the optimum tag orientation is determined, the orientation is used to perform range variation tests. The end goal of these tests is to find the maximum range at which the tags are readable under normal conditions using standard equipment. Grasping an idea of RFID tag boundaries contributes to the security and privacy of the technology. This is extremely important as RFID tags are becoming the logistical tool of choice for Department of Defense (DoD) supply chains. This fundamental study creates a foundation that may support both offensive and defensive oriented research. By understanding tag weaknesses and strengths, users of the technology can make sound decisions that lead to the protection of valuable information and assets

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

Definition, Characteristics and Determining Parameters of Antennas in Terms of Synthesizing the Interrogation Zone in RFID Systems

The radio frequency identification (RFID) systems are gaining in popularity in automated processes of object identification in various socioeconomic areas. However, despite the existing belief, there is no universal RFID system on the commercial market that could be used in all user applications. All components of a developed solution should be carefully selected or designed according to the specification of objects being recognized and characteristics of their environment. In order to determine parameters of propagation or inductively coupled system, especially when it is dedicated to uncommon applications, a multiaspect analysis has to be taken into consideration. Due to complexity, the problem is reduced to analytical or experimental determination of RFID system operation range and a “trial and error” method is mostly used in the industry practice. In order to cope with the barriers existing in the RFID technology, the authors give the review of latest achievements in this field. They focus on the definition, comprehensive characteristics and determination of the antenna parameters. They also pay attention to the 3D interrogation zone (IZ) that is the main parameter in which multitude technical aspects of the RFID systems are gathered simultaneously, as regards the theoretical synthesis as well as market needs

Passive low frequency RFID for non-destructive evaluation and monitoring

Ph. D ThesisDespite of immense research over the years, defect monitoring in harsh environmental conditions still presents notable challenges for Non-Destructive Testing and Evaluation (NDT&E) and Structural Health Monitoring (SHM). One of the substantial challenges is the inaccessibility to the metal surface due to the large stand-off distance caused by the insulation layer. The hidden nature of corrosion and defect under thick insulation in harsh environmental conditions may result in it being not noticed and ultimately leading to failures. Generally electromagnetic NDT&E techniques which are used in pipeline industries require the removal of the insulation layer or high powered expensive equipment. Along with these, other limitations in the existing techniques create opportunities for novel systems to solve the challenges caused by Corrosion under Insulation (CUI). Extending from Pulsed Eddy Current (PEC), this research proposes the development and use of passive Low Frequency (LF) RFID hardware system for the detection and monitoring of corrosion and cracks on both ferrous and non-ferrous materials at varying high temperature conditions. The passive, low cost essence of RFID makes it an enchanting technique for long term condition monitoring. The contribution of the research work can be summarised as follows: (1) implementation of novel LF RFID sensor systems and the rig platform, experimental studies validating the detection capabilities of corrosion progression samples using transient feature analysis with respect to permeability and electrical conductivity changes along with enhanced sensitivity demonstration using ferrite sheet attached to the tag; (2) defect detection using swept frequency method to study the multiple frequency behaviour and further temperature suppression using feature fusion technique; (3) inhomogeneity study on ferrous materials at varying temperature and demonstration of the potential of the RFID system; (4) use of RFID tag with ceramic filled Poly-tetra-fluoro-ethyulene (PTFE) substrate for larger applicability of the sensing system in the industry; (5) lift-off independent defect monitoring using passive sweep frequency RFID sensors and feature extraction and fusion for robustness improvement. This research concludes that passive LF RFID system can be used to detect corrosion and crack on both ferrous and non-ferrous materials and then the system can be used to compensate for temperature variation making it useful for a wider range of applications. However, significant challenges such as permanent deployment of the tags for long term monitoring at higher temperatures and much higher standoff distance, still require improvement for real-world applicability.Engineering and Physical Sciences Research Council (EPSRC) CASE, National Nuclear Laboratory (NNL)

Advanced power saving technologies for UHF band active RFID systems.

Wei Dacheng.Thesis (M.Phil.)--Chinese University of Hong Kong, 2006.Includes bibliographical references.Abstracts in English and Chinese.Table of Contents --- p.VIIIList of Tables --- p.XIList of Figures --- p.XIIList of Abbreviations --- p.XVChapter Chapter 1 --- IntroductionChapter 1.1 --- Introduction to RFID system --- p.1Chapter 1.2 --- Why we choose Active RFID system --- p.4Chapter 1.3 --- Objective of the research --- p.6Chapter 1.3.1 --- Requirement analysis --- p.7Chapter 1.3.2 --- Selection of RFID system and standard --- p.8Chapter 1.4 --- Original contribution of this dissertation --- p.9Chapter 1.5 --- Organization of the dissertation --- p.9Reference --- p.10Chapter Chapter 2 --- Implementation of An Active RFID SystemChapter 2.1 --- RFID System hardware design and related protocol --- p.1Chapter 2.2 --- Introduction to ISO 18000-7 --- p.7Chapter 2.3 --- Microcontroller specification --- p.12Chapter 2.4 --- RF model specifications --- p.14Chapter 2.5 --- Communication between a PC and a Reader --- p.15Chapter 2.6 --- Programming --- p.16Chapter 2.6.1 --- Procedure sequences of Reader and Tag --- p.17Chapter 2.6.2 --- Sequence of data transmission and reception --- p.24Chapter 2.6.3 --- CRC implementation --- p.28Chapter 2.7 --- Testing result --- p.31Reference --- p.35Chapter Chapter 3 --- Novel Power Saving Methods for an Active RFID SystemChapter 3.1 --- Some drawbacks of the existing Active RFID protocol --- p.1Chapter 3.1.1 --- Power consumption problem --- p.1Chapter 3.1.2 --- Multi-Reader problem --- p.9Chapter 3.2 --- Solutions of the Multi-Reader problem and power saving problem --- p.10Chapter 3.2.1 --- A solution to the power saving problem --- p.11Chapter 3.2.2 --- A solution to the Multi-Reader problem --- p.16Reference --- p.21Chapter Chapter 4 --- A Probe-fed Compact Half-wave Length Dipole Antenna for Active RFID SystemChapter 4.1 --- Requirement of an antenna for Active RFID system --- p.1Chapter 4.2 --- A probe-fed half-wave length dipole EE shape antenna for metallic object application --- p.2Chapter 4.3 --- Electromagnetic simulation results --- p.5Chapter 4.4 --- Operating principle analysis --- p.9Chapter 4.5 --- Using V shape structure to increase the bandwidth --- p.19Chapter 4.6 --- Prototyping and measurement results --- p.22Chapter 4.7 --- Conclusion --- p.28Reference --- p.29Chapter Chapter 5 --- Conclusio

RFID multiantenna systems for wireless communications and sensing

Many scientific, industrial and medical applications require the measurement of different physical parameters in order to collect information about the spatially distributed status of some process. Very often this information needs to be collected remotely, either due to the spatial dispersion of the measurement points or due to their inaccessibility. A wireless embedded self-powered sensor may be a convenient solution to be placed at these inaccessible locations. This thesis is devoted to study the analytical relation governing the electromagnetic coupling between a reader and a embeddable self-powered sensor, based on radio frequency identification (RFID) technology, which is capable of wirelessly retrieving the status of physical parameters at a remote and inaccessible location. The physical parameter to be sensed may be the electromagnetic (EM) field existing at that location (primary measurement) or the indirect measurement of other parameters such as the temperature, humidity, etc. (secondary measurement). Given the simplicity of the RFID solution (highly embeddable properties, scavenging capabilities, penetration and radio coverage characteristics, etc.) the measurement can be done at a single location, or it can be extended to a set of measuring locations (an array or grid of sensors). The analytical relation is based on a reciprocity formulation studying the modulation of the scattered field by the embedded sensor in relation with the incident field, and allows to define a set of quality parameters of interest for the optimum design of the sensors. Particular attention is given to the scavenging circuitry as well as to the antenna design relevant to the sensing objective. In RFID tags, the existence of an RF harvesting section is an improvement with respect to conventional scattering field probes since it removes the need of DC biasing lines or optical fibers to modulate the sensor. However, this harvesting section introduces non-linearities in the response of the sensor, which requires a proper correction to use them as EM-field probes, although the characterization of the non-linearities of the RFID tag cannot be directly done using a conventional vector network analyzer (VNA), due to the requirements of an RFID protocol excitation. Due to this, this thesis proposes an alternative measurement approach that allows to characterize the different scattering states used for the modulation, in particular its non-linear behavior. In addittion, and taking this characterization as the starting point, this thesis proposes a new measurement setup for EM-field measurements based on the use of multiple tones to enlarge the available dynamic range, which is experimentally demonstrated in the measurement of a radiation pattern, as well as in imaging applications. The RFID-based sensor response is electromagnetically sensitive to the dielectric properties of its close environment. However, the governing formulation for the response of the probe mixes together a set of different contributions, the path-loss, the antenna impedance, the loads impedance, etc. As a consequence, it is not possible to isolate each contribution from the others using the information available with a conventional RFID sensor. This thesis mathematically proposes and experimentally develops a modification of the modulation scheme to introduce a new set of multi-load scattering states that increases the information available in the response and properly isolate each term. Moreover, this thesis goes a step forward and introduces a new scattering state of the probe sensitive to temperature variations that do not depend on the environment characteristics. This new configuration enables robust environmental sensing in addition to EM-field measurements, and sensing variations of the dielectric properties of the environment

Sistemas eficientes de transmissão de energia sem-fios e identificação por radiofrequência

Doutoramento em Engenharia EletrotécnicaIn the IoT context, where billions of connected objects are expected to be ubiquitously deployed worldwide, the frequent battery maintenance of ubiquitous wireless nodes is undesirable or even impossible. In these scenarios, passive-backscatter radios will certainly play a crucial role due to their low cost, low complexity and battery-free operation. However, as passive-backscatter devices are chiefly limited by the WPT link, its efficiency optimization has been a major research concern over the years, gaining even more emphasis in the IoT context. Wireless power transfer has traditionally been carried out using CW signals, and the efficiency improvement has commonly been achieved through circuit design optimization. This thesis explores a fundamentally different approach, in which the optimization is focused on the powering waveforms, rather than the circuits. It is demonstrated through theoretical analysis, simulations and measurements that, given their greater ability to overcome the built-in voltage of rectifying devices, high PAPR multi-sine (MS) signals are capable of more efficiently exciting energy harvesting circuits when compared to CWs. By using optimal MS signals to excite rectifying devices, remarkable RF-DC conversion efficiency gains of up to 15 dB with respect to CW signals were obtained. In order to show the effectiveness of this approach to improve the communication range of passive-backscatter systems, a MS front-end was integrated in a commercial RFID reader and a significant range extension of 25% was observed. Furthermore, a software-defined radio RFID reader, compliant with ISO18000-6C standard and with MS capability, was constructed from scratch. By interrogating passive RFID transponders with MS waveforms, a transponder sensitivity improvement higher than 3 dB was obtained for optimal MS signals. Since the amplification and transmission of high PAPR signals is critical, this work also proposes efficient MS transmitting architectures based on space power combining techniques. This thesis also addresses other not less important issues, namely self-jamming in passive RFID readers, which is the second limiting factor of passive-backscatter systems. A suitable self-jamming suppression scheme was first used for CW signals and then extended to MS signals, yielding a CW isolation up to 50 dB and a MS isolation up 60 dB. Finally, a battery-less remote control system was developed and integrated in a commercial TV device with the purpose of demonstrating a practical application of wireless power transfer and passive-backscatter concepts. This allowed battery-free control of four basic functionalities of the TV (CH+,CH-,VOL+,VOL-).No contexto da internet das coisas (IoT), onde são esperados bilhões de objetos conectados espalhados pelo planeta de forma ubíqua, torna-se impraticável uma frequente manutenção e troca de baterias dos dispositivos sem fios ubíquos. Nestes cenários, os sistemas radio backscatter passivos terão um papel preponderante dado o seu baixo custo, baixa complexidade e não necessidade de baterias nos nós móveis. Uma vez que a transmissão de energia sem fios é o principal aspeto limitativo nestes sistemas, a sua otimização tem sido um tema central de investigação, ganhando ainda mais ênfase no contexto IoT. Tradicionalmente, a transferência de energia sem-fios é feita através de sinais CW e a maximização da eficiência é conseguida através da otimização dos circuitos recetores. Neste trabalho explora-se uma abordagem fundamentalmente diferente, em que a otimização foca-se nas formas de onda em vez dos circuitos. Demonstra-se, teoricamente e através de simulações e medidas que, devido à sua maior capacidade em superar a barreira de potencial intrínseca dos dispositivos retificadores, os sinais multi-seno (MS) de elevado PAPR são capazes de excitar os circuitos de colheita de energia de forma mais eficiente quando comparados com o sinal CW tradicional. Usando sinais MS ótimos em circuitos retificadores, foram verificadas experimentalmente melhorias de eficiência de conversão RF-DC notáveis de até 15 dB relativamente ao sinal CW. A fim de mostrar a eficácia desta abordagem na melhoria da distância de comunicação de sistemas backscatter passivos, integrou-se um front-end MS num leitor RFID comercial e observou-se um aumento significativo de 25% na distância de leitura. Além disso, desenvolveu-se de raiz um leitor RFID baseado em software rádio, compatível com o protocolo ISO18000-6C e capaz de gerar sinais MS, com os quais interrogou-se transponders passivos, obtendo-se ganhos de sensibilidade dos transponders maiores que 3 dB. Uma vez que a amplificação de sinais de elevado PAPR é uma operação crítica, propôs-se também novas arquiteturas eficientes de transmissão baseadas na combinação de sinais em espaço livre. Esta tese aborda também outros aspetos não menos importantes, como o self-jamming em leitores RFID passivos, tido como o segundo fator limitativo neste tipo de sistemas. Estudou-se técnicas de cancelamento de self-jamming CW e estendeu-se o conceito a sinais MS, tendo-se obtido isolamentos entre o transmissor e o recetor de até 50 dB no primeiro caso e de até 60 dB no segundo. Finalmente, com o objetivo de demonstrar uma aplicação prática dos conceitos de transmissão de energia sem fios e comunicação backscatter, desenvolveu-se um sistema de controlo remoto sem pilhas, cujo protótipo foi integrado num televisor comercial a fim de controlar quatro funcionalidades básicas (CH+,CH-,VOL+,VOL-)

Delay line based passive radio frequency identification tags

This work describes the concept, design, fabrication, and characterization of delay-based radio frequency identification (RFID) tags and RFID-based sensor tags, representing a novel RFID technology. The presented delay-based RFID concept is based on the LC-delay-line and transmission-delay-line based approaches. The proposed concept allows the realization of RFIDs and RFID-based sensor tags at any allowed radio frequency, with the limitation of realizing delay elements capable of producing required delays. The RFID configurations presented in this work are for operation at 915 MHz. Simulations are used to design and optimize components and devices that constitute the tags, and to integrate them to realize tags of different configuration. A set of fabrication processes has been developed for the realization of the tag. Characterization and field testing of these tags show that delay-based RFID approach can be used to make passive tags at ultra high frequency (UHF) and other allowed frequencies. Delay-based tags have the advantages of time domain operation, and the feasibility of complying with FCC regulations. However, size, need of isolators and circulator, and design constraints in producing higher number of bits are some of the concerns that need to be further addressed. In summary, this dissertation work presents a viable alternative RFID approach based on the delay line concept. The results obtained show great promise for further development and optimization of this approach for a wide range of commercial applications