Antenna Design for Mobile Devices

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.

• About the Author xPreface xiAcknowledgments xiiAbbreviations xiii1 Introduction 11.1 The Evolution of Mobile Antennas 21.2 How to Quantitatively Evaluate an Antenna 101.3 The Limits of Antenna Designs 121.4 The Trade‐Offs in Antenna Designs 141.5 Mobile Communication and Band Allocations 161.6 Quickly Building a Simple Antenna—a Practical Example 18References 272 Antenna Matching 282.1 The Smith Chart 292.2 Single‐Band Matching 332.2.1 Matching with Lumped Elements 332.2.2 Different Ways to Accomplish a Single‐Band Matching 362.2.3 Matching with Both Transmission Line and Lumped Elements 392.2.4 Bandwidth Consideration 422.3 Dual‐Band Matching 502.4 Reconfigurable Matching 552.4.1 Reconfigurable Matching—Varactor‐Based 552.4.2 Reconfigurable Matching—Switch‐Based 60References 633 External Antenna 653.1 Stubby Antennas 663.1.1 Single‐Band Helix Stubby Antenna 673.1.2 Multiband Helix Stubby Antenna 863.1.3 Ultra‐Wideband Stubby Antenna 1093.2 Whip–Stubby (Retractable) Antenna 1173.2.1 Decoupled Whip–Stubby Antenna 1193.2.2 Semi‐Decoupled Whip–Stubby Antenna 1213.3 Meander Line Stubby Antenna 1263.4 Effect of Ground Plane 131References 1364 Internal Antenna 1384.1 Inverted‐F Antenna 1414.2 Planar IFA 1464.2.1 Single‐Band PIFA 1464.2.2 Multiband PIFA Antenna with Slits 1494.2.3 Multiband PIFA with Separate Branches 1574.2.4 Multiband PIFA with Parasitic Element 1584.2.5 Manufacturing PIFA Antenna 1594.3 Folded Monopole Antenna 1634.4 Loop Antenna 1674.5 Ceramic Antenna 1724.5.1 Monopole‐Type Ceramic Antenna 1734.5.2 IFA‐Type Ceramic Antenna 1764.5.3 Loop‐Type Ceramic Antenna 1774.6 Slot Antenna 1794.7 Design a Hepta‐Band Antenna with Multiple Radiators and Multiple Modes 1854.8 Design a Reconfigurable Hepta‐Band Antenna 1914.9 MIMO Antennas 2004.9.1 Explaining Capacity Boost Effect Through the Antenna Point of View 2004.9.2 Antenna Correlation and Antenna Isolation 2074.9.3 Improve Isolation Between Antennas 2094.10 Antennas in Recently Released Phones 2114.10.1 Entry‐Level Phone 2114.10.2 Flagship Phone 221References 2265 Antenna Measurement 2295.1 Passive Antenna Measurement 2295.1.1 Measurement on a Vector Network Analyzer 2295.1.2 Fixture 2345.1.3 Passive Chamber Measurement 2465.2 Active Antenna (Over the Air) Measurement 2535.2.1 EIRP, ERP, and TRP 2535.2.2 EIS and TIS 2565.2.3 Sensitivity Degradation Due to Interference 2595.3 Antenna Measurements in the Production Line 2625.4 Multiple Input and Multiple Output Antenna Test 271References 2756 Regulations Related to Antenna Engineers 2766.1 Specific Absorption Rate 2766.1.1 Definition and Measurement Method of SAR 2776.1.2 SAR Limits in the United States and Europe 2836.1.3 Controlling SAR 2856.1.4 Updates on SAR Requirement 2946.2 Hearing Aid Compatibility 2966.2.1 HAC Measurement 2966.2.2 HAC Specification in the United States 2996.2.3 Updates on HAC Requirement 3036.3 Electromagnetic Compatibility 304References 305Appendix: User Manual for ZJ_Antenna_Matching Software 307Index 314