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Design Constraints for NFC Devices

Design Constraints for NFC Devices

Dominique Paret

ISBN: 978-1-848-21884-0

Apr 2016, Wiley-ISTE

224 pages

In Stock

$145.00

Description

Near field communication (NFC) can appear to be a simple intuitive technology for exchanging data between close devices. In reality, these contactless structures that combine components and antennas must respect important and specific working constraints.

Illustrated by a number of detailed technological examples, this book discusses the multiple normative (ISO, CEN, NFC Forum, EMVCo, etc.) and regulatory (ERC, FCC, ETSI, radiofrequency, private and ecological pollution, etc.) constraints, as well as the applied, typological, functional, structural, environmental or interoperability constraints that a NFC device might face.

Design Constraints for NFC Devices also presents techniques that enable us to free ourselves from the technological constraints of current NFC operations encountered in banking, public transport, administration, automotive, industrial, communicating object and Internet of Things applications.

Acknowledgements xi

Preface xiii

Introduction  xvii

Part 1. Introduction to – and Reminders About – NFC 1

Introduction to Part 1  3

Chapter 1. Recap of the Principles Employed in NFC  5

1.1. The physical fundaments of “contactless” and NFC 5

1.1.1. Phenomenon of propagation and radiation 5

1.1.2. Classification of fields and spatial regions 6

1.1.3. Spatial regions 6

1.1.4. Far field: r >> λ/2π (Fraunhofer zone) 6

1.1.5. Intermediary field: r approximately equal to λ (Fresnel zone) 7

1.1.6. Near field: r << λ/2π (Rayleigh zone) and the origin of NFC  7

1.1.7. Remarks on contactless, RFID and NFC applications  7

1.2. The concept of NFC  9

1.2.1. Biot–Savart law  10

1.2.2. Field H at a point on the axis of a circular antenna  10

1.2.3. Decrease in the field H as a function of “d” 13

1.2.4. Field H at a point on the axis of a rectangular antenna 14

Chapter 2. Normative Constraints of NFC 17

2.1. Introduction 17

2.1.1. Normative, regulatory and NFC market constraints  17

2.1.2. A little bit of vocabulary 18

2.1.3. Norm  19

2.1.4. Standard  19

2.2. Normative constraints 19

2.2.1. Uplink from initiator to targets 20

2.2.2. “Contactless” normative constraints on NFC device antennae  27

2.3. Conclusion 36

Chapter 3. Regulatory Constraints and Recommendations  39

3.1. Regulatory constraints specific to NFC and NFC antennas  39

3.1.1. State of RF regulations  39

3.1.2. Constraints pertaining to radiation and pollution by NFC  41

3.1.3. The ERC 70 03 recommendation and the ETSI 300 330 norm  41

3.2. Constraints due to recommendations  45

3.2.1. Exposure of the human body to EM fields  46

3.2.2. Societal constraints due to individual freedoms (privacy)  48

3.2.3. Environmental constraints  50

3.3. Constraints of the NFC market 52

3.3.1. NFC applications of short range devices 52

3.3.2. Costs and market prices desired by users 52

3.3.3. Beware of false advertising 53

Part 2. Constraints Due to the Field of Applications of NFC 55

Introduction to Part 2  57

Chapter 4. Applicational Typologies of the NFC and their Consequences 59

4.1. Applicational typologies of the NFC  59

4.1.1. Technologies 59

4.1.2. “NFC Forum Devices” and “NFC Forum Tags”  60

4.1.3. “Modes” of communication of an NFC Forum Device  62

4.1.4. Role of an NFC Forum Device 63

4.1.5. Applicational typological possibilities and their constraints 64

4.2. Application consequences and their direct constraints 67

4.2.1. Touch & Go typology  67

4.2.2. Touch & Confirm typology 67

4.2.3. Touch & Connect typology 67

4.2.4. Touch & Explore typology 68

Chapter 5. Constraints Due to Fields of Application  69

5.1. Range of technical possibilities of applications  69

5.1.1. In architectures and electronic functions 69

5.1.2. Shapes, dimensions and form factors (publicity aside)  70

5.1.3. Remarks and some clarifications about the table 70

5.1.4. Targets/tags for the monitoring of long-distance races  72

5.1.5. Targets/tags for monitoring luxury items 72

5.2. Segmentation, typologies of markets, their problems and their incidences, and direct technical constraints on NFC devices  73

5.2.1. Market sectors and typologies 74

5.3. Mobile telephony 75

5.4. Banks/money matters/payments 77

5.5. Transport  78

5.5.1. 1st case: card emulation mode in battery-assisted and then flat battery 81

5.5.2. 2nd case: card emulation mode with battery out  81

5.5.3. 3rd case: collisions and loading effects  82

5.6. Automobiles  82

5.6.1. Consumer electronics  85

5.7. Healthcare  88

5.8. Communicating objects  89

5.8.1. NFC tablets  89

5.8.2. NFC USB key 90

5.8.3. NFC communication and promotional objects  91

5.8.4. “Add-on” NFC devices, sticks, and stickers 92

Part 3. Applicational Constraints Needing to be Solved when Designing NFC Systems and their Antennas 95

Introduction to Part 3  97

Chapter 6. Structural Constraints in NFC  99

6.1. Constraints due to the form factors of the antennas  99

6.2. Constraints due to variations of the operating distance  100

6.2.1. Distances and magnetic couplings 100

6.3. Constraint of the maximum acceptable value of the quality coefficient Q of the initiator antenna  100

6.4. Constraint of the value of return (retro) modulation voltage 102

6.4.1. Passive Load Modulation (PLM) 103

6.4.2. Active Load Modulation (ALM) 106

Chapter 7. Functional Applicational Constraints  111

7.1. Antenna tuning/detuning constraints  111

7.1.1. The case of an initiator  111

7.1.2. Electrical representation of the target 112

7.1.3. “Tuned”, “untuned” and “detuned” mobile phones 120

7.2. Constraints and influences of the environment  124

7.2.1. Physical influence of the environment  124

7.2.2. Impacts of the environment on the antenna and its performance  124

7.2.3. Electrical fields E 125

7.2.4. Magnetic field 128

Part 4. Conformity and Interoperability Constraints 137

Introduction to Part 4  139

Chapter 8. Conformity Constraints  141

8.1. Conformity tests for NFC devices 141

8.2. Norms of “conformity” tests for NFC IPx 142

8.2.1. ISO 23917 tests (NFC IP1 protocol) 143

8.2.2. ISO 22536 tests (NFC IP1 RF interface)  143

8.3. Electrical characterizations of the initiator antenna 146

8.3.1. The antenna’s inductance and resistance 146

8.3.2. Quality coefficient  149

8.3.3. Bandwidth 149

8.3.4. Tuning of the antenna and its impedance matching 149

8.4. Method of adjustment of the target antenna  154

8.4.1. Absorption threshold, H_thr  154

8.4.2. Absorption in reading mode, H_read 154

8.4.3. Resonance frequency, f_res 154

8.4.4. Bandwidth 155

8.5. Measuring methods for use with the target  155

8.6. Electrical measurements of the initiator antenna 156

8.6.1. Measuring the magnetic field H radiated by the initiator 156

8.6.2. Measurement of the quality coefficient – Q 158

8.6.3. Measuring Q in the application 162

8.6.4. Measuring the bandwidth in the application 163

8.7. Method for adjustment of whole systems 165

8.7.1. Measurements needing to be performed 165

8.7.2. Order in which the measurements must be taken  165

8.7.3. Energy domains, zero lines, and safe operating areas 165

8.8. Measuring tools  166

Chapter 9. Interoperability Constraints 169

9.1. Norms and interoperability  169

9.2. Problems of the tests; JNCF ISO vs EMV vs NFC Forum; etc 170

9.2.1. EMV conformity tests . 171

9.3. In practice: a few simple examples of measurements  178

9.3.1. Example 1 179

9.3.2. Example 2 181

9.3.3. Conformity tests of the NFC Forum  185

9.3.4. NFC Forum testing and certification methods for the lower levels  186

9.3.5. Testing the conformity of NFC with the CEN – Comité européen de normalisation (European Standardizing Committee) 187

9.3.6. What about overall interoperability? 188

Conclusion 189

Bibliography  197

Index 199