About the Authors ix

Preface xi

Acknowledgments xiii



1 Introduction 1

References 4



2 Considerations for Microwave and Millimeter-Wave 5G Mobile Antenna Design 5

2.1 Frequency Characteristics and Channel Models 6

2.2 5G Network Architecture 12

2.3 Evolution of Mobile Devices 14

2.4 Antenna Materials 15

2.4.1 Laminated Sheet 16

2.4.2 Ceramic 17

2.4.3 Organic 19

2.4.4 Others 21

2.5 Conclusion 22

References 22



3 Basic Concepts for 5G FR1 Band Mobile Antenna Design 25

3.1 Design Considerations 25

3.1.1 Antenna Placement 26

3.1.2 Smartphone Components and Their Effects 27

3.2 Antenna Element Design and Topologies 34

3.2.1 Slot Antenna Design 35

3.2.2 Monopole Antenna Design 36

3.2.3 Loop Antenna 39

3.2.4 Inverted-F Antenna 43

3.3 Antenna-Feeding Mechanism and Impedance Matching 45

3.4 Chassis Consideration and Effects 47

3.5 Electromagnetic Exposure and Mitigation 49

3.5.1 Monopole Antenna Array User’s Hand Effects 52

3.5.2 Slot Antenna Array User’s Hand Effects 52

3.5.3 Loop Antenna Array User’s Hand Effects 55

3.6 Conclusion 55

References 57



4 Multi-Band 5G FR1 Band Mobile Antenna Design 61

4.1 Planar Antenna Design Topologies 62

4.1.1 Dual Band and Wideband Loop Antenna 62

4.1.2 Dual Band and Wideband Monopole Antenna 67

4.1.3 Dual Band and Wideband Slot Antenna 69

4.1.4 Dual Band PIFA and Dual Band Monopole 76

4.2 Hybrid Antenna Design Topologies 77

4.2.1 Separated Slot and Monopole 77

4.2.2 Integrated and Tightly Arranged Slot and Monopole 83

4.2.3 Tightly Arranged Loop and Monopole 86

4.2.4 Tightly Arranged Loop and Slot 94

4.2.5 Integrated Loop and IFA 94

4.3 Co-existence with 3G/4G and Millimeter-Wave 5G Antenna Techniques 98

4.3.1 Integrated 4G and 5G Sub-6 GHz Antennas 99

4.3.2 Integrated 4G and 5G mmWave Antennas 103

4.3.3 Miniaturized 5G Module of mmWave Antennas-in-Package Integrating Non-mmWave Antennas (AiPiA) 109

4.4 Wideband Antenna Design Topologies Beyond Band n77/n78/n79 110

4.5 Conclusion 119

References 119



5 MIMO-Based 5G FR1 Band Mobile Antenna 125

5.1 Motivation and Requirements 126

5.1.1 Channel Capacity 128

5.1.2 Envelope Correlation Coefficient 129

5.1.3 Diversity Gain 131

5.1.4 Mean Effective Gain 131

5.1.5 Total Active Reflection Coefficient 132

5.1.6 Channel Capacity Loss 133

5.2 Antenna Isolation Techniques 133

5.2.1 Spatial and Polarization Diversity 137

5.2.2 Neutralization Line 137

5.2.3 Slotted Element 143

5.2.4 Wave Trap Element 143

5.2.5 Self-Isolated Element 146

5.2.6 Others 152

5.3 Practical Considerations and Challenges 158

5.4 Conclusion 160

References 161



6 Millimeter-Wave 5G Antenna-in-Package (AiP) for Mobile Applications 167

6.1 Miniaturized Antenna-in-Package (AiP) Technology 169

6.1.1 Background and Challenges 169

6.1.2 Planar Folded Slot Antenna (PFSA) with Electrically Small and Low Profile 170

6.1.3 Low-Loss Interconnect Technology 178

6.1.4 Flip-Chip-Based Packaging of mmWave AiP 182

6.2 Multi-Modal AiP Technology 186

6.2.1 Block Cell Antennas 190

6.2.2 Modular, Controllable Block Cell Arrays 195

6.3 Conclusion 206

References 206



7 Multi-Physical Approach for Millimeter-Wave 5G Antenna-in-Package 211

7.1 Background and Current Challenges 211

7.2 Heat Dissipation Strategies 214

7.2.1 Metal Stamped Antenna-in-Package Overview 214

7.2.2 Proof-of-Concept Model 215

7.3 Multiphysical Analysis 217

7.3.1 Antenna Package Characterization 217

7.3.2 Electrical Stability of the Fabrication Process 220

7.3.3 Thermal-Mechanical Analysis 221

References 224



8 Frequency Tunable Millimeter-Wave 5G Antenna-in-Package 227

8.1 Background and Realistic Challenges for Mobile Applications 229

8.2 Tunable Matching Network 232

8.3 Topology and Design Considerations 234

8.4 Examples and Demonstrations 245

8.5 Upcoming Challenges 256

References 260



9 Cost-Effective and Compact Millimeter-Wave 5G Antenna Solutions 263

9.1 Background 263

9.1.1 Challenging Issues of Conventional Printing and Packaging Techniques in mmWave Antenna 265

9.1.2 Previous Researches on Mutual Coupling in Planar Multiple Antenna 267

9.1.3 Previous Researches on Low-Loss Feeding Networks 272

9.2 Compact Inverted-L Antenna Element with 1-D EBG Structures 274

9.2.1 1-D EBG Ground Structures and Their Electromagnetic Characteristics 276

9.2.2 Compact ILA with 1-D EBG Ground Structures 279

9.3 Low-Coupled mmWave Phased-Arrays Fabricated on FR-4 PCB 282

9.3.1 Design of Single Antenna Element with HIS Structures 282

9.3.2 Compact Phased Array Antenna in 4 Elements 284

9.3.3 8-Elements Large-Scaled Linear Array Antenna 290

9.4 Conclusion 296

References 299



10 Millimeter-Wave Antenna-on-Display for 5G Mobile Devices 303

10.1 Performance Metrics of mmWave 5G Mobile Antenna Systems 305

10.1.1 Spherical Coverage Requirements 305

10.1.2 Error Vector Magnitude (EVM) Requirement 306

10.2 Optically Invisible Antenna-on-Display Concept 307

10.2.1 Material and Process 308

10.2.2 Parametric Studies on Material Thickness and Width 309

10.2.3 Optically Transparent Antenna with Corrugated Edges 310

10.2.4 Optically Invisible Antenna with Dummy-Grids 312

10.3 OLED Display-Integrated Optically Invisible Phased-Arrays 315

10.3.1 Packaging Strategy 317

10.3.2 Component- and System-Level Verifications 319

10.4 OLED Touch Display-Integrated Optically Invisible Phased Arrays 321

10.4.1 Flexible, Invisible Hybrid Electromagnetic Sensor 322

10.4.2 Design Process and Building Block Measurements 323

10.4.2.1 Antenna Electrodes 325

10.4.2.2 Touch Sensor Electrodes 326

10.4.2.3 Wave-Trapped Dummy Electrodes 327

10.4.3 Demonstration within a Cellular Handset Prototype 329

10.5 Conclusion 334



References 335

Index