Analysis and design of metal-surface mounted radio frequency identification (RFID) transponders

With the development of the radio frequency integrated circuit (RFIC), contactless radio frequency identification (RFID) technology, as one of the fastest growing sectors of automatic identification procedures (Auto-ID), gains broad application in tracking assets in supply chain management. However, one of the largest challenges for the RFID industry is that the ultra high frequency (UHF) RFID transponder doesn\u27t function well when it is applied to any conductive surface. In this dissertation, the communication principle of wireless transceivers is illustrated. As one fast-growing application field of wireless communication, the distinct operating principle of the RFID is clarified. The factors that limit the reading/writing distance of UHF RFID transponders are discussed in detail. Some potential solutions are proposed and verified. One nondestructive solution is to apply a metamaterial such as a frequency selective surface (FSS) or a mushroom-like electromagnetic bandgap (EBG) surface to block the transmission of electromagnetic waves from the RFID antenna to the metal ground and thus boost the antenna radiation efficiency. For this solution, a new design approach suppressing the TM wave but supporting the TE wave is demonstrated. Another low-cost solution is to use an inexpensive substrate material and obtain the most power-efficient antenna structure. More than six potentially patentable planar RFID transponder antennas were invented, designed and tested. Their compact size, low profile, low cost and superior performance paves the way for the RFID industry to expand their market share in the near future

Introduction to Radio-frequency Identification (RFID)

This project presents the fundamental aspects of the RFID (Radio-frequency identifica-tion) technology used to establish wireless communications. The project focuses on thepassive mode of RFID, where the receiver does not have any power supply, which allowsits miniaturization and low cost.On the other hand, two articles from different authors are analyzed. The first consists onthe design of a very low power passive receiver through various techniques of optimizationin the hardware’s manufacture.In the second, a drone is used as an intermediate element between the transmitter and thereceiver to extend up to 10 times the typical range of passive RFID. The study focuses onthe treatment of the RF signal to considerably eliminate the interferences and to preciselylocalize the receiver.Outgoin

Nanopower CMOS transponders for UHF and microwave RFID systems

At first, we present an analysis and a discussion of the design options and tradeoffs for a passive microwave transponder. We derive a set of criteria for the optimization of the voltage multiplier, the power matching network and the backscatter modulator in order to optimize the operating range. In order to match the strictly power requirements, the communication protocol between transponder and reader has been chosen in a convenient way, in order to make the architecture of the passive transponder very simple and then ultra-low-power. From the circuital point of view, the digital section has been implemented in subthreshold CMOS logic with very low supply voltage and clock frequency. We present different solutions to supply power to the transponder, in order to keep the power consumption in the deep sub-µW regime and to drastically reduce the huge sensitivity of the subthreshold logic to temperature and process variations. Moreover, a low-voltage and low-power EEPROM in a standard CMOS process has been implemented. Finally, we have presented the implementation of the entire passive transponder, operating in the UHF or microwave frequency range

Design and construction of a 12kV D.C. power supply

An experimental work on a modified version of the so-called Cockroft-Walton type voltage multiplying rectifier was carried out. This involved the study of the factors governing the output voltage of the Cockroft-Walton multiplier, designing a multiplier based on these factors that can yield the targeted output voltage of over 10 kV, and the construction of a 12-kV d.c voltage generator. Essentially, the constructed generator is a modified 32-stage Cockroft-Walton type voltage multiplying rectifier. It is suitable as a power supply for the nitrogen laser. It can also be used in particle acceleration. The results of the study of the factors governing the output of the Cockroft-Walton multiplier, the components type and specification, and the construction and performance of the generator are presented and discussed Keywords: Design, Power, Construction, Cockrof

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

A low power signal front-end for passive UHF RFID transponders with a new clock recovery circuit.

Chan, Chi Fat.Thesis (M.Phil.)--Chinese University of Hong Kong, 2009.Includes bibliographical references.Abstracts in English and Chinese.Abstract --- p.2摘要 --- p.5Acknowledgement --- p.7Table of Contents --- p.9List of Figures --- p.11List of Tables --- p.14Chapter 1. --- Introduction --- p.15Chapter 1.2. --- Research Objectives --- p.16Chapter 1.3. --- Thesis Organization --- p.18Chapter 1.4. --- References --- p.19Chapter 2. --- Overview of Passive UHF RFID Transponders --- p.20Chapter 2.1. --- Types of RFID Transponders and Design Challenges of Passive RFID Transponder --- p.20Chapter 2.2. --- Selection of Carrier Frequency --- p.22Chapter 2.3. --- Description of Transponder Construction --- p.22Chapter 2.3.1. --- Power-Generating Circuits --- p.23Chapter 2.3.2. --- Base Band Processor --- p.28Chapter 2.3.3. --- Signal Front-End --- p.29Chapter 2.4. --- Summary --- p.30Chapter 2.5. --- References --- p.31Chapter 3. --- ASK Demodulator for EPC C-l G-2 Transponder --- p.32Chapter 3.1. --- ASK Demodulator Design Considerations --- p.32Chapter 3.1.1. --- Recovered Envelope Distortion --- p.32Chapter 3.1.2. --- Input Power Level Considerations --- p.34Chapter 3.1.3. --- Input RF power Intercepted by ASK Demodulator --- p.36Chapter 3.2. --- ASK Demodulator Design From [3-4] --- p.36Chapter 3.2.1. --- Envelope Waveform Recovery Design --- p.37Chapter 3.2.1.1. --- Voltage Multiplier Branch for Generating Venv --- p.39Chapter 3.2.1.2. --- Voltage Multiplier Branch for Generating Vref --- p.41Chapter 3.2.2. --- Design Considerations for Sensitivity of ASK Demodulator --- p.41Chapter 3.2.3. --- RF Input Power Sharing with Voltage Multiplier --- p.44Chapter 3.2.4. --- ASK Demodulator and Voltage Multiplier Integrated Estimations for Maximum RF Power Input --- p.47Chapter 3.2.5. --- Measurement result and Discussion --- p.49Chapter 3.3. --- Proposed Envelope Detector Circuit --- p.52Chapter 3.3.1. --- Sensitivity Estimation --- p.52Chapter 3.3.2. --- Maximum Tolerable Input Power Estimation --- p.53Chapter 3.3.3. --- Envelope Waveform Recovery of the Proposed Envelope Detector --- p.54Chapter 3.4. --- Summary --- p.57Chapter 3.5. --- References --- p.58Chapter 4. --- Clock Generator for EPC C-l G-2 Transponder --- p.59Chapter 4.1. --- Design Challenges Overview of Clock Generator --- p.59Chapter 4.2. --- Brief Review of PIE Symbols in EPC C1G2 Standard --- p.62Chapter 4.3. --- Proposed Clock Recovery Circuit Based on PIE Symbols for Clock Frequency Calibration --- p.64Chapter 4.3.1. --- Illustration on PIE Symbols for Clock Frequency Calibration --- p.64Chapter 4.3.2. --- Symbol time-length counter --- p.72Chapter 4.3.3. --- The M2.56MHZ Reference Generator and Sampling Frequency Requirement --- p.75Chapter 4.3.4. --- Symbol Length Reconfiguration for Different Tari and FLL Stability --- p.80Chapter 4.3.5. --- Frequency Detector and Loop Filter --- p.83Chapter 4.3.6. --- Proposed DCO Design --- p.84Chapter 4.3.7. --- Measurement Results and Discussions --- p.88Chapter 4.3.7.1. --- Frequency Calibration Measurement Results --- p.89Chapter 4.3.7.2. --- Number x and Tari Variation --- p.92Chapter 4.3.7.3. --- Temperature and Supply Variation --- p.93Chapter 4.3.7.4. --- Transient Supply Variation --- p.94Chapter 4.3.8. --- Works Comparison --- p.95Chapter 4.4. --- Clock Generator with Embedded PIE Decoder --- p.96Chapter 4.4.1. --- Clock Generator for Transponder Review --- p.96Chapter 4.4.2. --- PIE Decoder Review --- p.97Chapter 4.4.3. --- Proposed Clock Generator with Embedded PIE Decoder --- p.97Chapter 4.4.4. --- Measurement Results and Discussions --- p.100Chapter 4.5. --- Summary --- p.103Chapter 4.6. --- References --- p.105Chapter 5. --- ASK Modulator --- p.107Chapter 5.1. --- Introduction to ASK Modulator in RFD Transponder --- p.107Chapter 5.2. --- ASK Modulator Design --- p.109Chapter 5.3. --- ASK Modulator Measurement --- p.110Chapter 5.4. --- Summary --- p.113Chapter 5.5. --- References --- p.113Chapter 6. --- Conclusions --- p.114Chapter 6.1. --- Contribution --- p.114Chapter 6.2. --- Future Development --- p.11

Miniaturized antenna and transponder based wireless sensors for internet of things in healthcare

Future medical and healthcare systems will be largely improved by the wide-spreading of internet of things (IoTs). One of the crucial challenges of IoTs for healthcare is at the wireless sensors. Miniaturization of sensor node profile, minimizing power consumption as well as lowering down design/production cost of antenna, RF circuits and sensor modules have become the key issues for realizing more exciting applications in medical and healthcare fields that never seemed to be possible before. In this dissertation work, we first focus on electrically small antenna (ESA) design and fabrication for medical telemetry. A comprehensive analysis of the radiation properties of a novel electrically small folded ellipsoidal ESA is presented, showing its ability to self-resonate and impedance match without external components. It will benefit various size-restricted applications especially with wireless medical implants. The second focus is on healthcare sensors using ESA as the sensing agent, which saves the power and cost by eliminating the need of extra sensing modules. Specifically, miniaturized helix ESAs are integrated with drug reservoirs to function as wireless transponder sensors for real-time drug dosage monitoring. We also introduce a system level innovation of a passive wireless harmonic transponder/harmonic sniffer/frequency hopped interrogator based sensing system. The μL- liquid level resolution and absolute-accuracy passive sensing is demonstrated in the presence of strong direct coupling, background scatters, distance variance as well as near-filed human body movement interference. Furthermore, we investigate how modern ubiquitous wireless sensor networks could take advantage of sensitive nanostructure materials for enhanced performance. Here we propose a new paradigm of chemically-gated mixed modulation on a single homogeneous graphene device in which the chemical exposure directly modulates an electrical carrier signal. To make the device ubiquitously reusable, a method of precisely tuning the charge neutrality point (Vcnp) is introduced by electrochemical calibration with gate voltage pulse sequence. Such chemically gated graphene modulator can be potentially used in a harmonic transponder as a passive ubiquitous sensor node for chemical and bio sensing applications. Overall the research work presented in the dissertation will help enable cost and power-efficient wireless sensor networks in future healthcare IoTs.Electrical and Computer Engineerin

Next generation RFID telemetry design for biomedical implants.

The design and development of a Radio Frequency Identification (RFID) based pressure-sensing system to increase the range of current Intra-Ocular Pressure (IOP) sensing systems is described in this dissertation. A large number of current systems use near-field inductive coupling for the transfer of energy and data, which limits the operational range to only a few centimeters and does not allow for continuous monitoring of pressure. Increasing the powering range of the telemetry system will offer the possibility of continuous monitoring since the reader can be attached to a waist belt or put on a night stand when sleeping. The system developed as part of this research operates at Ultra-High Frequencies (UHF) and makes use of the electromagnetic far field to transfer energy and data, which increases the potential range of operation and allows for the use of smaller antennas. The system uses a novel electrically small antenna (ESA) to receive the incident RF signal. A four stage Schottky circuit rectifies and multiplies the received RF signal and provides DC power to a Colpitts oscillator. The oscillator is connected to a pressure sensor and provides an output signal frequency that is proportional to the change in pressure. The system was fabricated using a mature, inexpensive process. The performance of the system compares well with current state of the art, but uses a smaller antenna and a less expensive fabrication process. The system was able to operate over the desired range of 1 m using a half-wave dipole antenna. It was possible to power the system over a range of at least 6.4 cm when the electrically small antenna was used as the receiving antenna

High Voltage Energy Harvesters

Green energy helps in reducing carbon emission from fossil fuel, harvesting energy from natural resources like wind to power consumer appliances. To date, many researches have been focusing on designing circuits that harvest energy from electromagnetic signals wirelessly. While it could be designed to be efficient, the generated power however is insufficient to drive large loads. Wind energy is highly available environmentally but development of small-scale energy harvesting apparatus aiming to extract significant power from miniature brushless fan has received limited attention. The aim of this chapter is to give audience an insight of different voltage multipliers used in energy harvester and knowledge on various circuit techniques to configure voltage multipliers for use in different high voltage applications. These include AC-DC converter, AC-AC converter and variable AC-DC converter