Small Antenna Handbook [Hardcover]

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.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 Foster’s Reactance Theorem and Smith Chart / 39

2.3 Fano’s 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

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