Antenna Theory

Preface xiii About the Companion Website xix 1 Antennas 1 1.1 Introduction 1 1.2 Types of Antennas 3 1.3 Radiation Mechanism 7 1.4 Current Distribution on a Thin Wire Antenna 15 1.5 Historical Advancement 18 1.6 Multimedia 21 References 22 2 Fundamental Parameters and Figures-of-Merit of Antennas 25 2.1 Introduction 25 2.2 Radiation Pattern 25 2.3 Radiation Power Density 35 2.4 Radiation Intensity 37 2.5 Beamwidth 40 2.6 Directivity 41 2.7 Numerical Techniques 55 2.8 Antenna Efficiency 60 2.9 Gain, Realized Gain 61 2.10 Beam Efficiency 65 2.11 Bandwidth 65 2.12 Polarization 66 2.13 Input Impedance 75 2.14 Antenna Radiation Efficiency 79 2.15 Antenna Vector Effective Length and Equivalent Areas 81 2.16 Maximum Directivity and Maximum Effective Area 86 2.17 Friis Transmission Equation and Radar Range Equation 88 2.18 Antenna Temperature 96 2.19 Multimedia 100 References 103 Problems 105 3 Radiation Integrals and Auxiliary Potential Functions 127 3.1 Introduction 127 3.2 The Vector Potential A for an Electric Current Source J 128 3.3 The Vector Potential F for A Magnetic Current Source M 130 3.4 Electric and Magnetic Fields for Electric (J) and Magnetic (M) Current Sources 131 3.5 Solution of the Inhomogeneous Vector Potential Wave Equation 132 3.6 Far-Field Radiation 136 3.7 Duality Theorem 137 3.8 Reciprocity and Reaction Theorems 138 References 143 Problems 143 4 Linear Wire Antennas 145 4.1 Introduction 145 4.2 Infinitesimal Dipole 145 4.3 Small Dipole 155 4.4 Region Separation 158 4.5 Finite Length Dipole 164 4.6 Half-Wavelength Dipole 176 4.7 Linear Elements Near or On Infinite Perfect Electric Conductors (PEC), Perfect Magnetic Conductors (PMC) and Electromagnetic Band-Gap (EBG) Surfaces 179 4.8 Ground Effects 203 4.9 Computer Codes 216 4.10 Multimedia 216 References 218 Problems 220 5 Loop Antennas 235 5.1 Introduction 235 5.2 Small Circular Loop 236 5.3 Circular Loop of Constant Current 250 5.4 Circular Loop with Nonuniform Current 259 5.5 Ground and Earth Curvature Effects for Circular Loops 268 5.6 Polygonal Loop Antennas 269 5.7 Ferrite Loop 270 5.8 Mobile Communication Systems Applications 272 5.9 Multimedia 272 References 275 Problems 277 6 Arrays: Linear, Planar, and Circular 285 6.1 Introduction 285 6.2 Two-Element Array 286 6.3 N-Element Linear Array: Uniform Amplitude and Spacing 293 6.4 N-Element Linear Array: Directivity 312 6.5 Design Procedure 318 6.6 N-Element Linear Array: Three-Dimensional Characteristics 319 6.7 Rectangular-to-Polar Graphical Solution 322 6.8 N-Element Linear Array: Uniform Spacing, Nonuniform Amplitude 323 6.9 Superdirectivity 345 6.10 Planar Array 348 6.11 Design Considerations 360 6.12 Circular Array 363 6.13 Multimedia 367 References 367 Problems 368 7 Antenna Synthesis and Continuous Sources 385 7.1 Introduction 385 7.2 Continuous Sources 386 7.3 Schelkunoff Polynomial Method 387 7.4 Fourier Transform Method 392 7.5 Woodward-Lawson Method 398 7.6 Taylor Line-Source (Tschebyscheff-Error) 404 7.7 Taylor Line-Source (One-Parameter) 408 7.8 Triangular, Cosine, and Cosine-Squared Amplitude Distributions 415 7.9 Line-Source Phase Distributions 416 7.10 Continuous Aperture Sources 417 7.11 Multimedia 420 References 420 Problems 421 8 Integral Equations, Moment Method, and Self and Mutual Impedances 431 8.1 Introduction 431 8.2 Integral Equation Method 432 8.3 Finite Diameter Wires 439 8.4 Moment Method Solution 448 8.5 Self-Impedance 455 8.6 Mutual Impedance Between Linear Elements 463 8.7 Mutual Coupling in Arrays 474 8.8 Multimedia 480 References 480 Problems 482 9 Broadband Dipoles and Matching Techniques 485 9.1 Introduction 485 9.2 Biconical Antenna 487 9.3 Triangular Sheet, Flexible and Conformal Bow-Tie, and Wire Simulation 492 9.4 Vivaldi Antenna 496 9.5 Cylindrical Dipole 500 9.6 Folded Dipole 505 9.7 Discone and Conical Skirt Monopole 512 9.8 Matching Techniques 513 9.9 Multimedia 523 References 524 Problems 525 10 Traveling Wave and Broadband Antennas 533 10.1 Introduction 533 10.2 Traveling Wave Antennas 533 10.3 Broadband Antennas 549 10.4 Multimedia 580 References 580 Problems 582 11 Frequency Independent Antennas, Antenna Miniaturization, and Fractal Antennas 591 11.1 Introduction 591 11.2 Theory 592 11.3 Equiangular Spiral Antennas 593 11.4 Log-Periodic Antennas 598 11.5 Fundamental Limits of Electrically Small Antennas 614 11.6 Antenna Miniaturization 619 11.7 Fractal Antennas 627 11.8 Multimedia 633 References 633 Problems 635 12 Aperture Antennas 639 12.1 Introduction 639 12.2 Field Equivalence Principle: Huygens' Principle 639 12.3 Radiation Equations 645 12.4 Directivity 648 12.5 Rectangular Apertures 648 12.6 Circular Apertures 667 12.7 Design Considerations 675 12.8 Babinet's Principle 680 12.9 Fourier Transforms in Aperture Antenna Theory 684 12.10 Ground Plane Edge Effects: The Geometrical Theory of Diffraction 702 12.11 Multimedia 707 References 707 Problems 709 13 Horn Antennas 719 13.1 Introduction 719 13.2 E-Plane Sectoral Horn 719 13.3 H-Plane Sectoral Horn 733 13.4 Pyramidal Horn 743 13.5 Conical Horn 756 13.6 Corrugated Horn 761 13.7 Aperture-Matched Horns 766 13.8 Multimode Horns 769 13.9 Dielectric-Loaded Horns 771 13.10 Phase Center 773 13.11 Multimedia 774 References 775 Problems 778 14 Microstrip and Mobile Communications Antennas 783 14.1 Introduction 783 14.2 Rectangular Patch 788 14.3 Circular Patch 815 14.4 Quality Factor, Bandwidth, and Efficiency 823 14.5 Input Impedance 826 14.6 Coupling 827 14.7 Circular Polarization 830 14.8 Arrays and Feed Networks 832 14.9 Antennas for Mobile Communications 837 14.10 Dielectric Resonator Antennas 847 14.11 Multimedia 858 References 862 Problems 867 15 Reflector Antennas 875 15.1 Introduction 875 15.2 Plane Reflector 875 15.3 Corner Reflector 876 15.4 Parabolic Reflector 884 15.5 Spherical Reflector 920 15.6 Multimedia 923 References 923 Problems 925 16 Smart Antennas 931 16.1 Introduction 931 16.2 Smart-Antenna Analogy 931 16.3 Cellular Radio Systems Evolution 933 16.4 Signal Propagation 939 16.5 Smart Antennas' Benefits 942 16.6 Smart Antennas' Drawbacks 943 16.7 Antenna 943 16.8 Antenna Beamforming 946 16.9 Mobile Ad hoc Networks (MANETs) 960 16.10 Smart-Antenna System Design, Simulation, and Results 964 16.11 Beamforming, Diversity Combining, Rayleigh-Fading, and Trellis-Coded Modulation 972 16.12 Other Geometries 975 16.13 Multimedia 976 References 976 Problems 980 17 Antenna Measurements 981 17.1 Introduction 981 17.2 Antenna Ranges 982 17.3 Radiation Patterns 1000 17.4 Gain Measurements 1003 17.5 Directivity Measurements 1010 17.6 Radiation Efficiency 1012 17.7 Impedance Measurements 1012 17.8 Current Measurements 1014 17.9 Polarization Measurements 1014 17.10 Scale Model Measurements 1019 References 1024 Appendix I: f (x)= sin(x) x 1027 Appendix II: fN(x)= * |sin(Nx) N sin(x) * |N =1, 3, 5, 10, 20 1029 Appendix III: Cosine and Sine Integrals 1031 Appendix IV: Fresnel Integrals 1033 Appendix V: Bessel Functions 1035 Appendix VI: Identities 1041 Appendix VII: Vector Analysis 1045 Appendix VIII: Method of Stationary Phase 1055 Appendix IX: Television, Radio, Telephone, and Radar Frequency Spectrums 1061 Index 1065