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

Radio frequency identification (RFID) tags are widely used in various electronic devices due to their low cost, simple structure, and convenient data reading. This topic aims to study the key technologies of ultra-high frequency (UHF) RFID tags and high-precision temperature sensors, and how to reduce the power consumption of the temperature sensor and the overall circuits while maintaining minimal loss of performance. Combined with the biomedicine, an innovative high-precision human UHF RFID chip for body temperature monitoring is designed. In this study, a ring oscillator whose output frequency is linearly related to temperature is designed and proposed as a temperature-sensing circuit by innovatively combining auxiliary calibration technology. Then, a binary counter is used to count the pulses, and the temperature is ultimately calculated. This topic designed a relaxation oscillator independent of voltage and current. The various types of resistors were used to offset the temperature deviation. A current mirror array calibration circuit is used to calibrate the process corner deviation of the clock circuit with a self-calibration algorithm. This study mainly contributes to reducing power consumption and improving accuracy. The total power consumption of the RF/analog front-end and temperature sensor is 7.65µW. The measurement error of the temperature sensor in the range of 0 to 60◦C is less than ±0.1%, and the accuracy of the output frequency of the clock circuit is ±2.5%

A Control Method to Reduce Interferences and Collisions between Multiple RFID Tags and RFID Readers

Radio frequency identification technology (RFID) is one of the fastest developing technologies today. Although it has significant performance in use of Auto-ID applications, the presence of multiple tags in a RFID system can lead to interferences between each tags which is called Collision. There are many method to overcome this issue and this project introduces the use of DS-CDMA technique to overcome this issue. The Simulink simulation environment is used to simulate the use of DS-CDMA in RFID system. The results obtained clearly show the concept of this method is leading to a solution for RFID collision issues. However, the further improvement in simulations and concept of the method is most recommended in future project work

Leitor RFID para a gama UHF baseado em software-defined radio

Mestrado em Engenharia Eletrónica e TelecomunicaçõesEsta dissertação apresenta a arquitetura, o desenvolvimento e a validação de um leitor de RFID para a banda de frequências de 860 MHz a 960 MHz (UHF). Na sua conceção foi usada uma abordagem baseada em sistemas de rádio definidos por software (SDR-Software-Defined Radio). O RFID é uma tecnologia que permite a identicação de objetos através de ondas eletromagnéticas. Um leitor RFID, também designado por reader, emite um sinal eletromagnético para uma ou várias tags, e estas respondem (também na forma de um sinal eletromagnético) com um número de identicação único. Esta tecnologia é muito versátil e pode ser aplicada ás mais diversas situações, tais como, identicação de animais, acesso a edifícios e identicação de objetos num armazém. Podem ser usadas diferentes bandas de frequência do espectro eletromagnético, tais como, as low frequencies (LF), as high frequencies (HF) e as ultra high frequencies (UHF). O SDR _e um paradigma de projeto de sistemas de rádio, onde os blocos analógicos responsáveis pelo processamento de sinal, são total ou parcialmente substituídos por blocos programáveis de processamento no domínio digital. Este conceito permite aos sistemas de rádio resultantes apresentarem uma maior flexibilidade e adaptabilidade face a alterações que possam surgir na arquitetura ou requisitos do sistema. A digitalização num sistema SDR pode ser efetuada em banda base, em frequência intermédia ou em RF. O sistema de rádio presente nesta dissertação consiste num leitor RFID funcional para o protocolo de comunicação RFID ISO 18000-6C, implementado numa arquitetura SDR com digitalização em banda base, na cadeia de transmissão e digitalização em frequência intermédia, na cadeia de receção.This MSc thesis presents the architecture, development and validation of a RFID reader for the frequency band of 860 MHz to 960 MHz (UHF). In its design, a Software-De ned Radio (SDR) approach was used. RFID is a technology that allows the identi cation of objects using electromagnetic waves. A RFID reader emits an electromagnetic signal to one or more tags, and these respond (also in the form of an electromagnetic signal) with a unique identi cation number. This technology is very versatile and can be applied to various situations, such as animal identi cation, building access and identi cation of objects in a warehouse. It can be used in di erent frequency bands of the electromagnetic spectrum, such as the low frequencies (LF), the high frequencies (HF) and ultra high frequencies (UHF). The SDR is a design paradigm of radio systems, in which analog blocks responsible for signal processing, are partially or completely replaced by programmable processing blocks in the digital domain. This concept allows the resulting radio systems to o er greater exibility and adaptability to changes that occur in the architecture or system requirements. The digitalization in a SDR system can be made at baseband, intermediate frequency (IF) or at RF. The radio system, presented in this dissertation, is a functional RFID reader working on the protocol communication ISO 18000-6C and implemented with a baseband digitization SDR architecture at the transmition path, and a IF digitalization at the receiver path

Ihmiskäsivarren mallintaminen puettaville passiivisille UHF RFID tunniste -sovelluksille

Radio frequency identification (RFID) technology is rapidly emerging within bio-medical engineering applications. Particularly in harsh and challenging environments, RFID provide fast and reliable item identification and tracking solution. In a typical RFID system objects to be identified are marked with tags, consisting of an antenna and an integrated circuit. The tags are wirelessly read by a stationary reader unit. In the future, wearable RFID tags integrated into daily clothing could provide multi-functional garments for real-time remote bio-monitoring of humans without any human involvement. At ultra-high frequencies (UHF) the human body is electrically a challenging application environment for the tag due to its high permittivity and high losses. Modelling of the human body for UHF is not a straightforward task. The body in close proximity tends to interact with the tag in a disadvantageous manner, resulting in severe overall tag performance degradation. However, an accurate human model is of paramount importance for future design and optimisation of wearable antennas. In this project, a novel wireless approach is used to develop a UHF human arm model for wearable antenna applications. A reference tag is designed and its response is practically measured when the tag is directly attached to the human arm. The response serves as a reference response. A simple homogenous cylinder is used in electromagnetic simulations to represent the human arm. The cylinder material is defined with the electrical parameter variables effective relative permittivity, ɛr,eff, and loss tangent, tan δ. The reference tag is simulated on the cylinder. By adjusting the variables εr,eff and tan δ properly, agreement is found between the reference response and the simulated tag response on the cylinder. The approach eliminates the need for any information about the electrical parameters of a particular tissue type. Further, the wireless approach removes the need for baluns or fixture required in wired tag antenna input impedance measurements. It is verified that the developed UHF human arm model is able to predict the wearable tag performance on the human arm with ±3 dB accuracy over the frequency band 800–1000 MHz. The simple human arm simulation model can hereby be used as a powerful tool for future wearable antenna design and optimisation.Radiotaajuinen tunnistustekniikka (engl. Radio Frequency Identification, RFID) löytää yhä enemmän ja enemmän sovelluskohteita lääketieteellisessä tekniikassa. Erityisesti vaikeissa sekä haastavissa ympäristöissä RFID mahdollistaa kohteen nopean ja luotettavan tunnistus- sekä seuranata-ratkaisun. Tyypillisessä RFID järjestelmässä tunnistettavat kohteet merkitään tunnisteilla, jotka koostuvat tunnisteantennista sekä mikropiiristä. Tunnisteita luetaan langattomasti stationaarisella lukijalaitteella. Tulevaisuudessa, vaatteisiin integroidut puettavat RFID tunnisteet mahdollistavat monitoimi-vaatekappaleita ihmisten langatonta ja reaaliaikaista biomonitorointia varten. UHF taajuuksilla (0.3–3 GHz) ihmiskehon korkea permittiivisyys sekä korkeat häviöt muodostavat sähköisesti haastavan sovelluskohteen tunnisteelle. Ihmiskehon mallintaminen UHF taajuuksille ei ole suoraviivainen tehtävä. Ihmiskeho vaikuttaa tämän lähistössä olevaan tunnisteeseen epäedullisesti, johtaen tunnisteen suorituskyvyn vakavaan heikkenemiseen. Tulevaisuudessa, ihmiskehon mallintaminen on kuitenkin erittäin tärkeä osa puettavien antennien suunnittelussa ja optimoinnissa. Tässä työssä esitetään uudenlainen langaton lähestymistapa ihmiskäsivarren mallintamiseen puettaville UHF sovelluksille. Tarkoituksena on mitata referenssitunnisteen vaste tunnisteen ollessa kiinni käsivarressa ja hyödyntää mitattua referenssivastetta mallin rakentamiseen. Käsivarsi mallinnetaan kenttäsimulaattorissa yksinkertaisella homogeenisella lieriöllä. Lieriölle annetaan sähköiset parametrimuuttujat suhteellinen permittiivisyys, εr,eff, sekä häviökerroin, tan δ, kuvamaan lieriön materiaalisisältöä. Asettamalla sähköisten parametrimuuttujien arvot oikein, referenssitunnisteen simuloitu vaste saadaan yhteensopivaksi mitatun referenssivasteen kanssa. Käytetty lähestymistapa ei vaadi tietämystä yksittäisten kudoksien sähköisistä ominaisuuksista tai kudoksien suuruuksista. Lisäksi esitetyssä langattomassa menetelmässä ei tarvita baluunia tai erillistä kiinnityskappaletta, toisin kuin tunnisteantennin sisäänmenoimpedanssin mittauksissa. Työssä vahvistetaan, että suunniteltu ihmiskäsivarren malli UHF taajuuksille kykenee ennustamaan puettavan tunnisteen suorituskyvyn ihmiskäsivarressa ±3 dB:n tarkkuudella taajuuskaistalla 800–1000 MHz. Suunniteltua yksinkertaista ihmiskäsivarren simulointimallia voidaan näin ollen jatkossa hyödyntää tehokkaana työkaluna puettavien antennien suunnittelussa sekä optimoinnissa

A Control Method to Reduce Interferences and Collisions between Multiple RFID Tags and RFID Readers

Radio frequency identification technology (RFID) is one of the fastest developing technologies today. Although it has significant performance in use of Auto-ID applications, the presence of multiple tags in a RFID system can lead to interferences between each tags which is called Collision. There are many method to overcome this issue and this project introduces the use of DS-CDMA technique to overcome this issue. The Simulink simulation environment is used to simulate the use of DS-CDMA in RFID system. The results obtained clearly show the concept of this method is leading to a solution for RFID collision issues. However, the further improvement in simulations and concept of the method is most recommended in future project work

Development of Automated Test Analysis, Methodology and Procedure for Interoperability Measure in ISO 18000-7 Active RFID

In today's modern development process, for all embedded systems including wireless devices, commercial off the shelf products form the basic building blocks of the design. Such projects, often confront interoperability conflicts mainly because of the incompatible assumptions made by the development engineers and many possible solutions available for every problem. Lack of standard procedures and a sound mathematical basis describing the interoperability verification process and electronic tools to aid the interoperability analysis is hindering development of interoperable systems. It is therefore essential to develop a methodology to analyze and develop an interoperable measure of the system during and after development. It is also important to develop tools that will aid interoperability analysis with minimum human supervision. As an example, active RFID systems conforming to standards such as ISO 18000-7 are designed to meet customer requirements. Apart from conforming to all the required standards, these RFID systems also need to be interoperable with each other. In simple terms the reader of any one vendor should be able to communicate with tags from all vendors.The first step in verifying interoperability is to determine all factors, including those not explicitly defined by the standard, and determining the extreme limits of operation of each factor. In designing the analysis tool, statistical concepts like analysis of variance will be used to determine the effect of one factor on other and to determine the minimum number of required factors in an experiment. Depending on controllable factors, uncontrollable factors and dependent factors, the minimum number of experiments will be designed using blocking and randomizing techniques. The confidence level associated each experiment will be calculated using the acceptance sampling technique. Finally a technique to compare experiments performed on the same or different setup is proposed.This method is not only limited to active RFID but has the potential to revolutionize interoperability verification process among all wireless devices communicating via a command - reply protocol. The developed procedures will assist in planning the development process and also help alter it where and when necessary while not only obeying the standard but also understanding the ultimate essence of it

Integration of RFID and Industrial WSNs to Create A Smart Industrial Environment

A smart environment is a physical space that is seamlessly embedded with sensors, actuators, displays, and computing devices, connected through communication networks for data collection, to enable various pervasive applications. Radio frequency identification (RFID) and Wireless Sensor Networks (WSNs) can be used to create such smart environments, performing sensing, data acquisition, and communication functions, and thus connecting physical devices together to form a smart environment. This thesis first examines the features and requirements a smart industrial environment. It then focuses on the realization of such an environment by integrating RFID and industrial WSNs. ISA100.11a protocol is considered in particular for WSNs, while High Frequency RFID is considered for this thesis. This thesis describes designs and implementation of the hardware and software architecture necessary for proper integration of RFID and WSN systems. The hardware architecture focuses on communication interface and AI/AO interface circuit design; while the driver of the interface is implemented through embedded software. Through Web-based Human Machine Interface (HMI), the industrial users can monitor the process parameters, as well as send any necessary alarm information. In addition, a standard Mongo database is designed, allowing access to historical and current data to gain a more in-depth understanding of the environment being created. The information can therefore be uploaded to an IoT Cloud platform for easy access and storage. Four scenarios for smart industrial environments are mimicked and tested in a laboratory to demonstrate the proposed integrated system. The experimental results have showed that the communication from RFID reader to WSN node and the real-time wireless transmission of the integrated system meet design requirements. In addition, compared to a traditional wired PLC system where measurement error of the integrated system is less than 1%. The experimental results are thus satisfactory, and the design specifications have been achieved

Modulated Backscatter for Low-Power High-Bandwidth Communication

<p>This thesis re-examines the physical layer of a communication link in order to increase the energy efficiency of a remote device or sensor. Backscatter modulation allows a remote device to wirelessly telemeter information without operating a traditional transceiver. Instead, a backscatter device leverages a carrier transmitted by an access point or base station.</p><p>A low-power multi-state vector backscatter modulation technique is presented where quadrature amplitude modulation (QAM) signalling is generated without running a traditional transceiver. Backscatter QAM allows for significant power savings compared to traditional wireless communication schemes. For example, a device presented in this thesis that implements 16-QAM backscatter modulation is capable of streaming data at 96 Mbps with a radio communication efficiency of 15.5 pJ/bit. This is over 100x lower energy per bit than WiFi (IEEE 802.11).</p><p>This work could lead to a new class of high-bandwidth sensors or implantables with power consumption far lower than traditional radios.</p>Dissertatio

Wireless Network Communications Overview for Space Mission Operations

The mission of the On-Board Wireless Working Group (WWG) is to serve as a general CCSDS focus group for intra-vehicle wireless technologies. The WWG investigates and makes recommendations pursuant to standardization of applicable wireless network protocols, ensuring the interoperability of independently developed wireless communication assets. This document presents technical background information concerning uses and applicability of wireless networking technologies for space missions. Agency-relevant driving scenarios, for which wireless network communications will provide a significant return-on-investment benefiting the participating international agencies, are used to focus the scope of the enclosed technical information