Antenna Design for Mobile Devices

Expanded and updated, this practical guide is a one-stop design reference containing all an engineer needs when designing antennas

• Integrates state-of-the-art technologies with a special section for step-by-step antenna design
• Features up-to-date bio-safety and electromagnetic compatibility regulation compliance and latest standards
• Newly updated with MIMO antenna design, measurements and requirements
• Accessible to readers of many levels, from introductory to specialist
• Written by a practicing expert who has hired and trained numerous engineers

Zhijun Zhang, Professor, Tsinghua University, Beijing, China. He holds rich industry experience, with senior positions as an antenna development engineer at Amphenol T&M Antennas, Nokia, and Apple, giving him a perspective of design practices at a number of different players in the mobile segment. Prior to Tsinghua, his academic career included a postdoctoral fellowship and research professorship at the University of Utah, and a position as Assistant Researcher at the University of Hawaii, where he continues to serve as Adjunct Professor. Zhang earned a B.S. in Microwave Engineering and an M.S. in Applied Physics at the University of Electronic Science and Technology of China, Chengdu. He holds a PhD in Electronic Engineering from Tsinghua University.

Preface xi

Acknowledgments xii

Abbreviations xiii

1 Introduction 1

1.1 The Evolution of Mobile Antennas 2

1.2 How to Quantitatively Evaluate an Antenna 10

1.3 The Limits of Antenna Designs 12

1.4 The Trade�]Offs in Antenna Designs 14

1.5 Mobile Communication and Band Allocations 16

1.6 Quickly Building a Simple Antenna—a Practical Example 18

References 27

2 Antenna Matching 28

2.1 The Smith Chart 29

2.2 Single�]Band Matching 33

2.2.1 Matching with Lumped Elements 33

2.2.2 Different Ways to Accomplish a Single�]Band Matching 36

2.2.3 Matching with Both Transmission Line and Lumped Elements 39

2.2.4 Bandwidth Consideration 42

2.3 Dual�]Band Matching 50

2.4 Reconfigurable Matching 55

2.4.1 Reconfigurable Matching—Varactor�]Based 55

2.4.2 Reconfigurable Matching—Switch�]Based 60

References 63

3 External Antenna 65

3.1 Stubby Antennas 66

3.1.1 Single�]Band Helix Stubby Antenna 67

3.1.2 Multiband Helix Stubby Antenna 86

3.1.3 Ultra�]Wideband Stubby Antenna 109

3.2 Whip–Stubby (Retractable) Antenna 117

3.2.1 Decoupled Whip–Stubby Antenna 119

3.2.2 Semi�]Decoupled Whip–Stubby Antenna 121

3.3 Meander Line Stubby Antenna 126

3.4 Effect of Ground Plane 131

References 136

4 Internal Antenna 138

4.1 Inverted�]F Antenna 141

4.2 Planar IFA 146

4.2.1 Single�]Band PIFA 146

4.2.2 Multiband PIFA Antenna with Slits 149

4.2.3 Multiband PIFA with Separate Branches 157

4.2.4 Multiband PIFA with Parasitic Element 158

4.2.5 Manufacturing PIFA Antenna 159

4.3 Folded Monopole Antenna 163

4.4 Loop Antenna 167

4.5 Ceramic Antenna 172

4.5.1 Monopole�]Type Ceramic Antenna 173

4.5.2 IFA�]Type Ceramic Antenna 176

4.5.3 Loop�]Type Ceramic Antenna 177

4.6 Slot Antenna 179

4.7 Design a Hepta�]Band Antenna with Multiple Radiators and Multiple Modes 185

4.8 Design a Reconfigurable Hepta�]Band Antenna 191

4.9 MIMO Antennas 200

4.9.1 Explaining Capacity Boost Effect Through the Antenna Point of View 200

4.9.2 Antenna Correlation and Antenna Isolation 207

4.9.3 Improve Isolation Between Antennas 209

4.10 Antennas in Recently Released Phones 211

4.10.1 Entry�]Level Phone 211

4.10.2 Flagship Phone 221

References 226

5 Antenna Measurement 229

5.1 Passive Antenna Measurement 229

5.1.1 Measurement on a Vector Network Analyzer 229

5.1.2 Fixture 234

5.1.3 Passive Chamber Measurement 246

5.2 Active Antenna (Over the Air) Measurement 253

5.2.1 EIRP, ERP, and TRP 253

5.2.2 EIS and TIS 256

5.2.3 Sensitivity Degradation Due to Interference 259

5.3 Antenna Measurements in the Production Line 262

5.4 Multiple Input and Multiple Output Antenna Test 271

References 275

6 Regulations Related to Antenna Engineers 276

6.1 Specific Absorption Rate 276

6.1.1 Definition and Measurement Method of SAR 277

6.1.2 SAR Limits in the United States and Europe 283

6.1.3 Controlling SAR 285

6.1.4 Updates on SAR Requirement 294

6.2 Hearing Aid Compatibility 296

6.2.1 HAC Measurement 296

6.2.2 HAC Specification in the United States 299

6.2.3 Updates on HAC Requirement 303

6.3 Electromagnetic Compatibility 304

References 305

Appendix: User Manual for ZJ_Antenna_Matching Software 307

Index 314

The New copy of this book will include any supplemental materials advertised. Please check the title of the book to determine if it should include any access cards, study guides, lab manuals, CDs, etc.

The Used, Rental and eBook copies of this book are not guaranteed to include any supplemental materials. Typically, only the book itself is included. This is true even if the title states it includes any access cards, study guides, lab manuals, CDs, etc.