Radio Wave Propagation Fundamentals, Second Edition

This completely updated second edition of an Artech House classic provides a thorough introduction to the basic principles of electromagnetic wave propagation of radio frequencies in real-world conditions, fully updated by including new achievements in theory and technology. It serves as an invaluable daily reference for practitioners in the field and as a complete, organized text on the subject. This comprehensive resource covers a wide range of essential topics, from the classification of radio waves, electromagnetic wave theory, and antennas for RF radio links, to the impact of the earth surface on the propagation of ground waves, atmospheric affects in radio wave propagation, and radio wave reception. The book explores the propagation of the ground radio waves, namely the waves that propagate in vicinity of the earth's surface (e.g., guided by that interface), without involvement of any atmospheric effects. Specifics of the high-frequency (HF) radio propagation due to reflections from ionospheric layers is studied, based on commonly used models of the ionospheric vertical profiles. Scattering of the radio waves of UHF and higher frequency bands from the random variations of the tropospheric refraction index (from tiny air turbulences) are also considered by using the principles of statistical radio-physics. Analysis of propagation conditions on real propagation paths, including analysis of the power budget of the VHF/UHF link to assure its stability (percentage of availability within observation time frame), terrestrial, broadcast, mobile, and satellite RF links are presented. The engineering design of the cellular networks, including LTE 4G, 5G and upcoming higher generations is explored. HF propagation predictions for extremely long-range links design for commercial and military applications are explained. Packed with examples and problems, this book provides a theoretical background for astrophysical, aeronomy and geophysical instrumentation design. Artech House Radar Series Radio Wave Propagation Fundamentals Second Edition 1 Contents 8 Preface to the Second Edition 12 Preface to the First Edition 14 Chapter 1 Introduction 18 1.1 Brief Historical Overview 18 1.2 Classification of Radio Waves by Frequency Bands 21 1.3 The Earth’s Atmosphere and Its Structure 23 1.4 Classification of Radio Waves by Its Propagation Mechanisms 28 1.5 Interferences in RF Transmission Links 32 References 35 Chapter 2 Basics of Electromagnetic Waves Theory 38 2.1 Electromagnetic Process 38 2.1.1 Maxwell’s Equations of Electrodynamiscs 38 2.1.2 Boundary Conditions of Electrodynamics 42 2.1.3 Time-Harmonic Electromagnetic Process: Classification of Media by Conductivity 48 2.2 Free Propagation of Uniform Plane Radio Waves 52 2.2.1 Uniform Plane Wave in Lossless Medium 57 2.2.2 Uniform Plane Wave in Lossy Medium 59 2.3 Polarization of the Radio Waves 64 2.3.1 Basic Relationships 65 2.3.2 Linear Polarization (LP) 66 2.3.3 Circular Polarization 67 2.3.4 Elliptical Polarization 69 2.4 Reflection and Refraction of Plane Radio Wave from the Boundary of Two Media 80 2.4.1 Introductory Remarks 80 2.4.2 Normal Incidence on a Plane Boundary 82 2.4.3 Oblique Incidence on a Plane Boundary 84 2.4.4 Power Reflection and Transmission 91 2.4.5 Reflection of the Radio Wave from the Boundary of Nonideal Dielectric Medium 93 2.5 Radiation from Infinitesimal Electric Current Source: Spherical Waves 93 2.6 Spatial Area Significant for Radio Waves Propagation 96 2.6.1 Huygens’ Principle 96 2.6.2 Fresnel Zones 98 2.6.3 Knife-Edge Diffraction 104 2.6.4 Some Practical Applications of the Fresnel Zones Concept 109 References 115 Appendix 2A Useful Mathematical Relations 115 2A.1 Trigonometric Equalities 115 2A.2 Vector Analysis 116 Appendix 2B Basic Relations in Infinitesimal Electric Current Source Radiation Analysis 118 2B.1 Helmholtz Equation for Vector Potential 118 2B.2 Radiation from the Electric Current Point Source 122 Appendix 2C Fresnel’s Integrals 126 Chapter 3 Basics of Antennas for RF Links 130 3.1 Brief Introduction 130 3.2 Basic Parameters of Antennas 130 3.2.1 Radiation Pattern and Directivity 131 3.2.2 Radiation Resistance, Loss Resistance, and Antenna Gain 137 3.2.3 Antenna Effective Length 139 3.2.4 Antenna Effective Area of the Aperture 145 3.3 General Relations in Radio Wave Propagation Theory 146 References 152 Appendix 3A Definition of the Antenna’s Far Field Zone 152 Chapter 4 Impact of the Earth Surface on Propagation of Ground Waves 154 4.1 Propagation Between Antennas Elevated Above the Earth’s Surface: Ray-Trace Approach 154 4.1.1 Flat Earth Approximation Case Study 155 4.1.2 Propagation over the Spherical Earth Surface 163 4.1.3 Specifics of Propagation over a Rough and Hilly Terrain 173 4.1.4 Optimal Path Clearance and Choice of the Antenna Elevations 179 4.1.5 Propagation Prediction Models in Urban, Suburban, and Rural Areas 181 4.2 Propagation Between Ground-Based Antennas over the Flat Earth 191 4.2.1 Antennas over the Infinite, Perfect Ground Plane 192 4.2.2 Leontovich Approximate Boundary Conditions and Structure of RadioWaves Near the Earth’s Surface 195 4.2.3 Propagation over the Real Homogeneous Flat Earth 201 4.2.4 Propagation Along the Real Inhomogeneous Flat Earth: Coastal Refraction 205 4.3 Asymptotic Diffraction Theory of Propagation over the Spherical Earth Surface 210 4.3.1 Basic Concepts 210 4.3.2 Propagation Between Ground-Based Antennas 215 4.3.3 Propagation Between Elevated Antennas 221 4.3.4 Specifics of Propagation Estimates in Penumbra Zone 223 References 228 Appendix 4A Input Impedance of the Radiating Current Element Above the PEC Ground Plane 229 Appendix 4B Diffraction of Radio Wave Around Earth’s Surface: Basic Theory 232 4B.1 General Solution of the Wave Equation Relevant to Propagation Factor 232 Appendix 4C Specifics of Ground Reflection Calculations Between Vertically Polarized Antennas 242 Appendix 4D Table of Roots (k) of Equation (4.56) for the Given Combination of p and x Parameters 245 Chapter 5 Atmospheric Effects in Radio Wave Propagation 246 5.1 Dielectric Permittivity and Conductivity of the Ionized Gas 246 5.2 Regular Refraction of the Radio Waves in the Atmosphere 251 5.3 Standard Atmosphere and Tropospheric Refraction 253 5.4 Reflection and Refraction of the Sky Waves in the Ionosphere 258 5.5 The Impact of the Earth’s Magnetic Field on Propagation of the Radio Waves in the Ionosphere 264 5.5.1 Propagation Along Geomagnetic Field Lines 266 5.5.2 Propagation Perpendicular to Geomagnetic Field Lines 270 5.5.3 Propagation of the Radio Wave Arbitrary Oriented Relative to the Earth’s Magnetic Field 272 5.5.4 Reflection and Refraction of the Radio Waves in the Magneto-Active Ionosphere 275 5.6 Specifics of Ionospheric Propagation of ELF and VLF in the Earth-Ionosphere Waveguide 277 5.6.1 General Remarks 277 5.6.2 Propagation of ELF Signals 281 5.6.3 Propagation of LF and VLF Signals: High-Order Modes 282 5.7 Over-the-Horizon Propagation of the Radio Waves by the Tropospheric Scattering Mechanism 286 5.7.1 Secondary Tropospheric Radio Links 286 5.7.2 Analytical Approaches in Description of the Random Tropospheric Scatterings 288 5.7.3 Physical Interpretation of Tropospheric Scatterings 293 5.7.4 Effective Scattering Cross-Section of the Turbulent Troposphere 296 5.7.5 Statistical Models of Tropospheric Turbulences 297 5.7.6 Propagation Factor on Secondary Tropospheric Radio Links 303 5.7.7 The Specifics of the Secondary Tropospheric Radio Links Performance 308 5.8 Attenuation of the Radio Waves in the Atmosphere 313 5.8.1 Attenuations in Troposphere 313 5.8.2 Attenuations in Ionosphere 317 References 324 Appendix 5A Volumetric Spectrum for Autocorrelation Function of Statistically Homogeneous and Isotropic Random Field 325 Appendix 5B Some Theoretical Aspects of the Ionospheric Layers Generation 326 5B.1 Ionospheric Gaseous Composition and Physical Processes Related to Ionospheric Propagation 326 5B.2 Chapman Model and Structure of the Real Ionosphere 328 Appendix 5C Plane Wave Propagation in Homogeneous Magnetoactive Plasma of Ionosphere 332 5C.1 General Relations 332 5C.2 Propagation Along Geomagnetic Field Lines 333 5C.3 Propagation Across Geomagnetic Field Lines 338 Chapter 6 Fluctuation Processes, RF-Link Stability Analysis and Radio Wave Reception 342 6.1 Multiplicative Interferences (Signal Fades) 342 6.1.1 Fluctuation Processes and Stability of Radio Links 342 6.1.2 Fast Fading Statistical Distributions 348 6.1.3 Slow Fading Statistical Distribution 358 6.1.4 Combined Distribution of Fast and Slow Fades 363 6.2 Additive Interferences (Noises) 370 6.2.1 Internal Noises of One- and Two-Port Networks 370 6.2.2 Noise Figure and Noise Temperature of the Cascaded Two-Port Networks 373 6.2.3 Noise Figure of the Passive Two-Port Network 375 6.2.4 Antenna Noise Temperature 378 6.2.5 Environmental (External) Noise 379 6.2.6 Basics of RF Link Performance Stability Analysis 387 6.3 Methods of Improvement of RF Systems Performance 391 6.3.1 Use of Noise Suppressing Modems for the Analog RF Links Performance Improvement 392 Problems 410 References 411 Selected Bibliography 412 Acronyms 414 List of Symbols 416 About the Author 420 Radio,waves;,radio,propagation;,Radar;,Artech,House;,978-1-63081-844-9 Radio waves,radio propagation,Radar,Artech House,978-1-63081-844-9