COMMUNICATIONS-ELECTRONICS FUNDAMENTALS

« TC 9-64 COMMUNICATIONS-ELECTRONICS FUNDAMENTALS Wave Propagation, Transmission Lines, and Antennas JULY 2004 DISTRIBUTION RESTRICTION: Approved for public release; distribution is unlimited. HEADQUARTERS DEPARTMENT OF THE ARMY This publication is available at Army Knowledge Online www.us.army.mil *TC 9-64 Training Circular No.

9-64 Headquarters Department of the Army Washington, DC, 15 July 2004 Communications-Electronics Fundamentals: Wave Propagation, Transmission Lines, and Antennas Contents Page Preface Chapter 1 ..........................................................................................................................

ix WAVE PROPAGATION.....................................................................................

1-1 Learning Objectives .............................................................................................................................

1-1 What is Propagation?..........................................................................................................................

1-2 Principles of Wave Motion ..................................................................................................................

1-2 Sound Waves......................................................................................................................................1-15 Light Waves.........................................................................................................................................1-23 Electromagnetic Spectrum................................................................................................................1-30 Electromagnetic Waves.....................................................................................................................1-32 Summary..............................................................................................................................................1-39 Chapter 2 RADIO WAVE PROPAGATION .........................................................................

2-1 Learning Objectives .............................................................................................................................

2-1 Electromagnetic Fields ........................................................................................................................

2-2 Radio Waves.........................................................................................................................................

2-6 Summary..............................................................................................................................................2-38 Chapter 3 PRINCIPLES OF TRANSMISSION LINES ..........................................................

3-1 Learning Objectives .............................................................................................................................

3-1 Introduction to Transmission Lines....................................................................................................

3-1 Effect of Termination on Standing Waves......................................................................................3-42 Summary..............................................................................................................................................3-46 Chapter 4 ANTENNAS ......................................................................................................

4-1 Learning Objectives .............................................................................................................................

4-2 Radio Frequency Safety Precautions ...............................................................................................

4-2 Principles of Antenna Radiation.........................................................................................................

4-4 Current and Voltage Distribution on an Antenna.............................................................................

4-6 Radiation of Electromagnetic Energy................................................................................................

4-8 Antenna Characteristics ......................................................................................................................

4-9 Reciprocity of Antennas ....................................................................................................................4-10 Basic Antennas ...................................................................................................................................4-20 Summary..............................................................................................................................................4-54 DISTRIBUTION RESTRICTION: Approved for public release; distribution is unlimited. *This publication supersedes FM 11-64, 13 June 1985. i TC 9-64 _________________________________________________________________________ Appendix A Glossary References Index ii ..................................................................................................................................A-1 .....................................................................................................................Glossary-1 .................................................................................................................References-1 ...........................................................................................................................Index-1 ________________________________________________________________________Contents Figures Figure 1-1.

Formation of Waves in Water ..............................................................................1-3 Figure 1-2.

How a Falling Stone Creates Wave Motion on Water’s Surface .........................1-4 Figure 1-3.

Elements of a Wave .............................................................................................1-4 Figure 1-4.

Transverse Wave .................................................................................................1-5 Figure 1-5.

Sound Propagation by a Tuning Fork ..................................................................1-5 Figure 1-6.

The Three Elements of Sound .............................................................................1-6 Figure 1-7.

Comparison of Waves with Different Amplitudes.................................................1-7 Figure 1-8.

Longitudinal Wave Represented Graphically by a Transverse Wave .................1-9 Figure 1-9.

Reflection of a Wave ..........................................................................................1-12 Figure 1-10.

Refraction of a Wave .......................................................................................1-13 Figure 1-11.

Analogy of Reflection .......................................................................................1-14 Figure 1-12.

No Air, No Sound .............................................................................................1-17 Figure 1-13.

Musical Sound Versus Noise ...........................................................................1-18 Figure 1-14.

Sound Waves Spread in All Directions ............................................................1-19 Figure 1-15.

Combination of Tones......................................................................................1-20 Figure 1-16.

Refraction of Sound .........................................................................................1-22 Figure 1-17.

Waves and Radii from a Nearby Light Source.................................................1-25 Figure 1-18.

Use of a Prism to Split White Light into Different Colors .................................1-26 Figure 1-19.

Light Waves Reflected, Absorbed, and Transmitted .......................................1-27 Figure 1-20.

Transparent, Translucent, and Opaque Substances .......................................1-28 Figure 1-21.

Diffusion of Light ..............................................................................................1-30 Figure 1-22.

Electromagnetic Spectrum...............................................................................1-32 Figure 1-23.

Simple Radio Communication System.............................................................1-33 Figure 1-24.

Antenna............................................................................................................1-34 Figure 1-25.

Electric Fields between Plates .........................................................................1-36 Figure 1-26.

Electric Fields between Plates at Different Angles ..........................................1-36 Figure 1-27.

Electric Fields between Elements ....................................................................1-37 Figure 1-28.

Magnetic Fields around Elements....................................................................1-38 Figure 1-29.

Left-Hand Rule for Conducting Elements ........................................................1-39 Figure 1-30.

Relationship of E-Lines and Current Flow .......................................................1-40 Figure 1-Sum 1.

Formation of Waves in Water ....................................................................1-41 Figure 1-Sum 2.

Elements of a Wave ..................................................................................1-41 Figure 1-Sum 3.

The Three Elements of Sound...................................................................1-41 Figure 1-Sum 4.

Reflection of a Wave .................................................................................1-42 Figure 1-Sum 5.

Refraction of a Wave .................................................................................1-43 Figure 1-Sum 6.

Musical Sound Versus Noise.....................................................................1-44 Figure 1-Sum 7.

Use of a Prism to Split White Light into Different Colors...........................1-45 Figure 1-Sum 8.

Electromagnetic Spectrum ........................................................................1-46 Figure 2-1.

Induction Field about an Antenna ........................................................................2-3 Figure 2-2.

Phase Relationship of Induction Field Components ............................................2-4 iii TC 9-64 _________________________________________________________________________ Figure 2-3.

Radiation from an Antenna..................................................................................

2-5 Figure 2-4.

E and H Components of Induction and Radiation Fields ....................................

2-6 Figure 2-5.

Vertical and Horizontal Polarization ..................................................................

2-10 Figure 2-6.

Right-Hand Rule for Propagation ......................................................................

2-11 Figure 2-7.

Phase Shift of Reflected Radio Waves .............................................................

2-12 Figure 2-8.

Radio Wave Refraction......................................................................................

2-13 Figure 2-9.

Diffraction around an Object..............................................................................

2-14 Figure 2-10.

Layers of the Earth’s Atmosphere ...................................................................

2-15 Figure 2-11.

Ground Waves and Sky Waves ......................................................................

2-16 Figure 2-12.

Surface Wave Propagation..............................................................................

2-17 Figure 2-13.

Space Wave Propagation................................................................................

2-18 Figure 2-14.

Layers of the Ionosphere.................................................................................

2-21 Figure 2-15.

Effects of Ionospheric Density on Radio Waves .............................................

2-22 Figure 2-16.

Frequency Versus Refraction and Distance....................................................

2-23 Figure 2-17.

Different Incident Angles of Radio Waves.......................................................

2-23 Figure 2-18.

Effects of Frequency on the Critical Angle ......................................................

2-24 Figure 2-19.

Relationship between Skip Zone, Skip Distance, and Ground Wave .............

2-25 Figure 2-20.

Ray Paths for a Fixed Frequency with Varying Angles of Incidence ..............

2-26 Figure 2-21.

Multipath Transmission....................................................................................

2-28 Figure 2-22.

Freespace Loss Principle ................................................................................

2-29 Figure 2-23.

Refraction of Frequency below the Lowest Usable Frequency (LUF) ............

2-34 Figure 2-24.

RF Energy Losses from Scattering .................................................................

2-36 Figure 2-25.

Duct Effect Caused by Temperature Inversion ...............................................

2-37 Figure 2-26.

Tropospheric Scattering Propagation..............................................................

2-38 Figure 2-Sum 1.

Vertical and Horizontal Polarization ..........................................................

2-40 Figure 2-Sum 2.

Phase Shift of Reflected Radio Waves .....................................................

2-41 Figure 2-Sum 3.

Ground and Sky Waves ............................................................................

2-41 Figure 2-Sum 4.

Surface Wave Propagation .......................................................................

2-42 Figure 2-Sum 5.

Space Wave Propagation .........................................................................

2-42 Figure 2-Sum 6.

Layers of the Ionosphere ..........................................................................

2-43 Figure 2-Sum 7.

Frequency Versus Refraction and Distance .............................................

2-43 Figure 2-Sum 8.

Effects of Frequency on Critical Angle......................................................

2-44 Figure 2-Sum 9.

Relationship between Skip Zone, Skip Distance, and Ground Wave.......

2-44 Figure 2-Sum 10.

Multipath Transmission ...........................................................................

2-45 Figure 2-Sum 11.

Refraction of Frequency below the Lowest Usable Frequency (LUF) .......................................................................................................................

2-45 Figure 2-Sum 12.

Duct Effect Caused by Temperature Inversion.......................................

2-46 Figure 2-Sum 13.

Tropospheric Scattering Propagation .....................................................

2-46 Figure 3-1.

Basic Transmission Line......................................................................................

3-2 Figure 3-2.

Parallel Two-Wire Open Line...............................................................................

3-3 Figure 3-3.

Two-Wire Ribbon Line .........................................................................................

3-3 Figure 3-4.

Twisted Pair .........................................................................................................

3-4 Figure 3-5.

Shielded Pair .......................................................................................................

3-4 Figure 3-6.

Rigid (Air) Coaxial Line........................................................................................

3-5 iv ________________________________________________________________________Contents Figure 3-7.

Flexible (Solid) Coaxial Line ................................................................................3-6 Figure 3-8.

Waveguides .........................................................................................................3-6 Figure 3-9.

Equivalent Circuit of a Two-Wire Transmission Line .........................................3-11 Figure 3-10.

Distributed Inductance .....................................................................................3-11 Figure 3-11.

Distributed Capacitance...................................................................................3-12 Figure 3-12.

Distributed Resistance .....................................................................................3-12 Figure 3-13.

Leakage in a Transmission Line ......................................................................3-13 Figure 3-14.

Fields between Conductors .............................................................................3-13 Figure 3-15.

Short Section of Two-Wire Transmission Line and Equivalent Circuit ............3-15 Figure 3-16.

Characteristic Impedance ................................................................................3-16 Figure 3-17 Termination of a Line ........................................................................................3-18 Figure 3-18.

DC Voltage Applied to a Line...........................................................................3-20 Figure 3-19.

AC Voltage Applied to a Transmission Line ....................................................3-20 Figure 3-20.

DC Applied to an Equivalent Transmission Line..............................................3-21 Figure 3-21.

AC Applied to an Equivalent Transmission Line.............................................3-22 Figure 3-22.

Instantaneous Voltages along a Transmission Line ........................................3-23 Figure 3-23.

DC Applied to an Equivalent Transmission Line..............................................3-25 Figure 3-24.

Reflection from an Open-Ended Line...............................................................3-29 Figure 3-25.

Reflection from a Short-Circuited Line .............................................................3-31 Figure 3-26.

Formation of Standing Waves..........................................................................3-32 Figure 3-27.

Instantaneous Values of Incident and Reflected Waves on an OpenEnded Line ..............................................................................................................3-34 Figure 3-28.

Conventional Picture of Standing Waves ........................................................3-35 Figure 3-29.

Composite Results of Instantaneous Waves ...................................................3-36 Figure 3-30.

Standing Waves on a Shorted Line .................................................................3-37 Figure 3-31.

Sending-End Impedance of Various Lengths and Terminations .....................3-39 Figure 3-32.

Voltage, Current, and Impedance on Open Line .............................................3-41 Figure 3-33.

Voltage, Current, and Impedance on Shorted Line .........................................3-42 Figure 3-34.

Effects of Various Terminations on Standing Waves.......................................3-44 Figure 3-Sum 1.

Two-Wire Open Line..................................................................................3-48 Figure 3-Sum 2.

Two-Wire Ribbon Type Line ......................................................................3-48 Figure 3-Sum 3.

Twisted Pair ...............................................................................................3-48 Figure 3-Sum 4.

Shielded Pair .............................................................................................3-49 Figure 3-Sum 5.

Rigid (Air) Coaxial Line..............................................................................3-49 Figure 3-Sum 6.

Flexible (Solid) Coaxial Lines ....................................................................3-49 Figure 3-Sum 7.

Waveguides ...............................................................................................3-50 Figure 3-Sum 8.

Equivalent Circuit of a Two-Wire Transmission Line.................................3-50 Figure 3-Sum 9.

Distributed Constants ................................................................................3-51 Figure 3-Sum 10.

Leakage in a Transmission Line..............................................................3-51 Figure 3-Sum 11.

Fields between Conductors .....................................................................3-52 Figure 3-Sum 12.

Characteristic Impedance........................................................................3-52 Figure 3-Sum 13.

Formation of Standing Wave ...................................................................3-53 Figure 3-Sum 14.

Instantaneous Values of Incident and Reflected Waves.........................3-53 Figure 3-Sum 15.

Voltage, Current, and Impedance on a Shorted Line..............................3-54 v TC 9-64 _________________________________________________________________________ Figure 3-Sum 16.

Various Termination Effects on Standing Waves ...................................

3-55 Figure 4-1.

Satellite/Earth Station Communications System .................................................

4-1 Figure 4-2.

Warning Signs for Radio Frequency Radiation Hazards.....................................

4-3 Figure 4-3.

Typical Antenna System......................................................................................

4-5 Figure 4-4.

Typical Antennas .................................................................................................

4-6 Figure 4-5.

Current and Voltage Distribution on a Antenna...................................................

4-7 Figure 4-6.

Antenna and RF Source ......................................................................................

4-8 Figure 4-7.

Standing Waves of Voltage and Current on an Antenna ....................................

4-9 Figure 4-8.

Reciprocity of Antenna ......................................................................................

4-11 Figure 4-9.

Satellite Transmissions Using Polarized Radiation ...........................................

4-13 Figure 4-10.

Isotropic Radiator ............................................................................................

4-15 Figure 4-11.

Comparison of Rectangular and Polar-Coordinate Graph for an Isotropic Source.....................................................................................................................

4-16 Figure 4-12.

Anisotropic Radiator ........................................................................................

4-19 Figure 4-13.

Polar-Coordinate Graph for Anisotropic Radiator ...........................................

4-20 Figure 4-14.

Electrically Equal Antenna...............................................................................

4-22 Figure 4-15.

Development of Vertical and Horizontal Pattern .............................................

4-23 Figure 4-16.

Radiation Pattern of a Dipole ..........................................................................

4-24 Figure 4-17.

Standing Waves of Current and Voltage .........................................................

4-25 Figure 4-18.

Mobile Antennas..............................................................................................

4-26 Figure 4-19.

Grounded Quarter-Wave Antenna Image .......................................................

4-26 Figure 4-20.

Ground Screen and Counterpoise...................................................................

4-27 Figure 4-21.

Folded-Dipole Antennas ..................................................................................

4-28 Figure 4-22.

Phasing of Antenna in Free Space..................................................................

4-31 Figure 4-23.

Phasing of Connected Elements .....................................................................

4-32 Figure 4-24.

Directivity and Interference..............................................................................

4-33 Figure 4-25.

Single Antenna Versus Array ..........................................................................

4-34 Figure 4-26.

Single Half-Wave Antenna versus Two Half-Wave Antenna in Phase ...........

4-35 Figure 4-27.

Typical Broadside Array ..................................................................................

4-37 Figure 4-28.

Parallel Elements in Phase..............................................................................

4-38 Figure 4-29.

Typical End-Fire Array.....................................................................................

4-39.... »