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
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.