Now in an completely revised, updated, and enlarged Second Edition,Small Antennas in Portable Devices reviews recent significant theoretical and practical developments in the electrically small antenna area. Examining antenna designs that work as well as those that have limitations, this new edition provides practicing engineers and upper level and graduate students with new information on: work on improving bandwidth using spherical helix dipoles; work on electromagnetically coupled structures; exact derivation of the Q for electrically small antennas for both the TE and TM modes; and a new simplified Q formula.

Robert C. Hansen, PhD, DEng, has had a long and distinguished career in the aerospace industry. Beginning in 1949, he held key posts in a number of leading aerospace companies, including The Aerospace Corp., STL, Inc. (now TRW), and Hughes Aircraft Co. He is a Fellow of IEEE and IEE and is a member of the National Academy of Engineering. Since 1971, Dr. Hansen has been a consulting engineer for antennas and systems-related problems.

The LateRobert Collin, PhD, taught at Case Reserve Western University, where he was chairman of the Department of Electrical Engineering and Applied Physics. He was an invited professor at Pontifical Catholic University of Rio de Janeiro; Telebras Research Center, Brazil; and Beijing University, China. Dr. Collin was the author or coauthor of five books and more than 150 technical papers.

PREFACE xiii

1. QUALITY FACTORS OF ESA 1

1.1 Introduction / 1

1.2 Chu Antenna Q / 4

1.3 Collin and Rothschild Q Analysis / 8

1.4 Thal Antenna Q / 14

1.5 Radian Sphere with Mu and/or Epsilon: TE Modes / 16

1.6 Radian Sphere with Mu and/or Epsilon: TM Modes / 22

1.7 Effects of Core Losses / 28

1.8 Q for Spheroidal Enclosures / 34

References / 36

2. BANDWIDTH AND MATCHING 39

2.1 Introduction / 39

2.2 Fosters Reactance Theorem and Smith Chart / 39

2.3 Fanos Matching Limitations / 41

2.4 Matching Circuit Loss Magnification / 46

2.5 Network and Z0 Matching / 48

2.6 Non-Foster Matching Circuits / 50

2.7 Matched and High-Z Preamp Monopoles / 51

2.7.1 A Short Monopole Matched at One Frequency / 52

2.7.2 Short Monopole with High-Impedance Amplifier / 54

References / 55

3. ELECTRICALLY SMALL ANTENNAS: CANONICAL TYPES 59

3.1 Introduction / 59

3.2 Dipole Basic Characteristics / 59

3.2.1 Dipole Impedance and Bandwidth / 59

3.2.2 Resistive and Reactive Loading / 67

3.2.3 Other Loading Configurations / 76

3.2.4 Short Flat Resonant Dipoles / 78

3.2.5 Spherical Helix Antennas / 82

3.2.6 Multiple Resonance Antennas / 84

3.2.6.1 Spherical Dipole; Arc Antennas / 84

3.2.6.2 Multiple Mode Antennas / 86

3.2.6.3 Q Comparisons / 87

3.2.7 Evaluation of Moment Method Codes for Electrically Small Antennas / 88

3.3 Partial Sleeve, PIFA, and Patch / 93

3.3.1 Partial Sleeve / 93

3.3.2 PIFA Designs / 94

3.3.3 Patch with Permeable Substrate / 98

3.4 Loops / 101

3.4.1 Air Core Loops, Single and Multiple Turns / 101

3.4.2 Permeable Core Loops / 107

3.4.3 Receiving Loops / 114

3.4.4 Vector Sensor / 116

3.5 Dielectric Resonator Antennas / 120

References / 127

4. CLEVER PHYSICS, BUT BAD NUMBERS 135

4.1 Contrawound Toroidal Helix Antenna / 135

4.2 Transmission Line Antennas / 138

4.3 Halo, Hula Hoop, and DDRR Antennas / 138

4.4 Dielectric-Loaded Antennas / 140

4.5 Meanderline Antennas / 141

4.6 Cage Monopole / 142

References / 143

5. PATHOLOGICAL ANTENNAS 147

5.1 Crossed-Field Antenna / 147

5.2 Infinite Efficiency Antenna / 149

5.3 EH Antenna / 150

5.4 TETM Antenna / 150

5.5 Crossed Dipoles / 151

5.6 Snyder Dipole / 152

5.7 Loop-Coupled Loop / 155

5.8 Multiarm Dipole / 158

5.9 Complementary Pair Antenna / 158

5.10 Integrated Antenna / 159

5.11 Q 0 Antenna / 160

5.12 Antenna in a NIM Shell / 161

5.13 Fractal Antennas / 162

5.14 Antenna on a Chip / 170

5.15 Random Segment Antennas / 171

5.16 Multiple Multipoles / 171

5.17 Switched Loop Antennas / 173

5.18 Electrically Small Focal Spots / 174

5.19 ESA Summary / 174

References / 175

6. SUPERDIRECTIVE ANTENNAS 181

6.1 History and Motivation / 181

6.2 Maximum Directivity / 182

6.2.1 Apertures / 182

6.2.2 Arrays / 183

6.2.2.1 Broadside Arrays of Fixed Spacing / 183

6.2.2.2 Endfire Arrays / 186

6.2.2.3 Minimization Codes / 192

6.2.2.4 Resonant Endfire Arrays / 192

6.3 Constrained Superdirectivity / 194

6.3.1 DolphChebyshev Superdirectivity / 194

6.3.2 Superdirective Ratio Constraint / 198

6.3.3 Bandwidth or Q Constraint / 200

6.3.4 Phase or Position Adjustment / 200

6.3.5 Tolerance Constraint / 201

6.4 Bandwidth, Efficiency, and Tolerances / 201

6.4.1 Bandwidth / 201

6.4.2 Efficiency / 205

6.4.3 Tolerances / 208

6.5 Miscellaneous Superdirectivity / 209

6.6 Superdirective Antenna Summary / 210

References / 210

7. SUPERCONDUCTING ANTENNAS 215

7.1 Introduction / 215

7.2 Superconductivity Concepts for Antenna Engineers / 215

7.3 Dipole, Loop, and Patch Antennas / 221

7.3.1 Loop and Dipole Antennas / 222

7.3.2 Microstrip Antennas / 223

7.3.3 Array Antennas / 225

7.3.4 Millimeter-Wave Antennas / 229

7.3.4.1 Waveguide Flat Plane Array / 229

7.3.4.2 Microstrip Planar Array / 230

7.3.5 Submillimeter Antennas / 232

7.3.6 Low-Temperature Superconducting Antennas / 232

7.4 Phasers and Delay Lines / 233

7.5 Superconducting Antenna Summary / 236

References / 236

APPENDIX A A WORLD HISTORY OF ELECTRICALLY SMALL ANTENNAS 243

APPENDIX B DEFINITIONS OF TERMS USEFUL TO ESA 277

APPENDIX C SPHERICAL SHELL OF ENG METAMATERIAL SURROUNDING A DIPOLE ANTENNA 279

APPENDIX D FREQUENCY DISPERSION LIMITS RESOLUTION IN VESELAGO LENS 307

AUTHOR INDEX 335

SUBJECT INDEX 343