Electromagnetic Waves 2 examines antennas in the field of radio waves. It analyzes the conditions of use and the parameters that are necessary in order to create an effective antenna.
This book presents antennas’ definitions, regulations and fundamental equations, and describes the various forms of antennas that can be used in radio: horns, waveguides, coaxial cables, printed and miniature antennas. It presents the characterization methods and the link budgets as well as the digital methods that make the fine calculation of radio antennas possible.
Electromagnetic Waves 2 is a collaborative work, completed only with the invaluable contributions of Ibrahima Sakho, Hervé Sizun and JeanPierre Blot, not to mention the editor, Pierre-Noël Favennec. Aimed at students and engineers, this book provides essential theoretical support for the design and deployment of wireless radio and optical communication systems.
Preface ix
Chapter 1. General Information on Antennas 1
Jean-Pierre BLOT
1.1. Definition, context, and regulation 1
1.1.1. The International Union of Telecommunications and Radio communications (ITU-R) 9
1.1.2. Frequency bands: uses and classification (see also appendices 3 and 5) 10
1.1.3. Review of some technologies by frequency bands (see also appendices 3 and 5) 12
1.2. Propagation and radiation 19
1.3. Antenna and sensor 20
1.3.1. Antenna operating in transmission and reception 23
1.4. Theorems and important principles of electromagnetism 27
1.4.1. Lorentz reciprocity theorem 27
1.4.2. Huygens-Fresnel principle 28
1.4.3. Uniqueness theorem 30
1.4.4. Image theory 30
1.4.5. Superposition principle 30
Chapter 2. Fundamental Equations Used in Antenna Design 31
Jean-Pierre BLOT
2.1. Formulations of Maxwell’s equations to calculate the radiation of electromagnetic sources 31
2.1.1. Maxwell’s equations 32
2.1.2. Material media 34
2.1.3. Vectors D and H 36
2.1.4. Source currents and induced currents 42
2.1.5. Integral form of Maxwell’s equation 44
2.2. Boundary conditions between two media 44
2.3. Vector potential 47
2.3.1. Propagation equations for the vector potential 50
2.3.2. Propagation equations for the scalar potential 52
2.3.3. Vector and scalar potentials in the harmonic regime 53
2.4. Propagation equation for fields E and H 54
2.5. Solving the Helmholtz equations for the vector and scalar potentials 55
2.5.1. Orthogonality of distance fields zone and radiated power; radiation pattern 57
2.6. Harmonic form of Maxwell’s equations 61
2.7. Physical interpretation of the Poynting theorem 61
2.7.1. Poynting vector in the time domain 61
2.7.2. Poynting vector in the frequency domain 64
2.8. Polarized wave 65
2.8.1. Definition of a plane wave 65
2.8.2. Polarizations of a wave 66
2.9. Calculating the electromagnetic field radiated by an antenna 72
2.9.1. Expanded discussion of the EFIE and MFIE formulae 72
2.9.2. Calculations for an elementary dipole 73
2.10. Aperture antenna 76
2.10.1. Wireless radiation of apertures 76
2.10.2. Identification of the different zones 80
Chapter 3. Different Antenna Technologies 85
Jean-Pierre BLOT
3.1. Horns 85
3.2. Coaxial cables and input guides in antennas 87
3.2.1. Coaxial cables 89
3.2.2. Waveguides 91
3.3. Supply to antennas, reference access, impedance matching and balun 105
3.3.1. Supply lines 105
3.3.2. Reference access 105
3.3.3. Matching networks 107
3.3.4. Baluns and symmetrizers 109
3.4. Reflector antennas 110
3.5. Printed antennas 115
3.5.1. Low-bandwidth structures 116
3.5.2. High-bandwidth structures, or frequency-independent structures 121
3.6. Reference wire antennas 122
3.7. Quality factor and frequency bandwidth 123
3.7.1. Quality factor 123
3.7.2. Frequency bandwidth 124
3.8. Miniaturization 125
Chapter 4. Characteristic Parameters of an Antenna 131
Jean-Pierre BLOT
4.1. Characteristic parameters of an antenna 131
4.1.1. Capture surfaces or equivalent surfaces on an antenna 132
4.1.2. Directivity and gain 133
4.1.3. Relation between gain, directivity and radiation pattern 135
4.1.4. Effective height or effective length 136
4.2. Link budget 138
4.3. Power and noise temperature 140
4.3.1. Noise temperature received by an antenna 143
4.3.2. Link budget and Friis formula 144
4.4. Quality factor Q = G/T 145
Chapter 5. Digital Methods 149
Jean-Pierre BLOT
5.1. Introduction to digital methods 149
5.1.1. Overview of the main digital methods 149
5.1.2. Hybridization of digital methods 155
5.1.3. Low-frequency methods 155
5.1.4. Introduction to high-frequency methods 189
5.2. General remarks on EMC methods 195
Appendix 1 197
Appendix 2 201
Appendix 3 219
Appendix 4 227
Appendix 5 231
List of Acronyms and Constants 233
References 235
List of Authors 243
Index 245
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