Antennas & Wave Propagation(AWP) Class Lecture Notes JNTUK Syllabus:

AWP Lecture Notes
(AWP)Antennas and Wave Propagation Class Lecture Notes


(AWP) Class Lecture Notes:


UNIT 1 : Antenna Fundamentals

Antenna Fundamentals: Introduction, Radiation mechanism - Single wire, 2 wire. Dipoles. Current distribution on a thin wire antenna. Antenna parameters - Radiation patterns. Patterns in principal planes, Main lobe and side lobes. Beam widths, Beam area, Radiation intensity. Beam efficiency. Directivity. Gain and resolution, Antenna apertures. Aperture efficiency. Effective height Related problems.

Contents

1.1 Introduction
1.2 Definitions of Antenna
1.3 Functions of Antenna
1.4 Important Properties of Antenna
1.5 Basic Antenna Elements
1.6 Sources of Radiation and Radiation Mechanism
1.7 Current Distribution on Thin Wire Antenna
1.8 Types of Antenna
1.9 Antenna Fundamentals
1.10 Isotropic Radiator
1.11 Basic Antenna Parameters
1.12 Radiation Pattern
1.13 Radian, Steradian and Beam Solid Angle(4)
1.14 Radiation Intensity [U (0, )]
1.15 Directive Gain [G, (, ) and Directivity[D]
1.16 Directivity and Resolution
1.17 Power Gain [G, (0, )) and Radiation Efficiency (or Antenna Efficiency)
1.18 Front to Back Ratio (FBR)
1.19 Antenna Beamwidth
1.20 Antenna Beam Efficiency (t , )
1.21 Antenna Bandwidth (Ao)
1.22 Input impedance of Antenna
1.23 Self and Mutual Impedance of Antenna
1.24 Radiation Resistance
1.25 Effective Length (or Effective Height)
1.26 Effective Aperture or Effective Area [A,]
1.27 Radio Communication Link - Friis Transmission Formula
1.28 Fields from Oscillating Dipole
1.29 Field Zones of Antenna
1.30 Shape-impedance Considerations

UNIT 2 : Thin Linear Wire Antennas

Thin Linear Wire Antennas : Retarded potentials, Radiation from small electric dipole.Quarter Wave monopole and half wave dipole - Current Distributions, Evaluation of field components. Power radiated. Radiation resistance, Beamwidths, Directivity, Effective area and effective height Natural current distributions, Fields and patterns of thin linear center-fed antennas of different lengths. Radiation resistance at a point which is not the current maximum. Antenna theorems - Applicability and proofs for equivalence of directional characteristics.

Contents

2.1 Introduction
2.2 Potential Functions and Electromagnetic Fields
2.3 Potential Functions for Time Periodic Fields
2.4 Radiation from Alternating Current Element
2.5 he Hertzian Dipole - Radiation between a Current Element and Electric Dipole
2.6 Power Radiated by a Current Element
2.7 Short Linear Antennas
2.8 The Half Wave Dipole and the Monopole
2.9 Near Field due to Sinusoidal Current Distribution
2.10 Current Distribution on Thin Wire Antenna
2.11 Antenna Theorems


UNIT 3: Loop Antenna

Loop Antennas: Small loops- Field components, Comparison of far fields of small loop and short dipole, Concept of short magnetic dipole, Dand R, relationsfor small loops.

Contents

3.1 Introduction
3.2 Basics of Loop Antenna
3.3 Field Pattern of Small Loop Antenna
3.4 Comparison of Small Loop with Short Dipole
3.5 General Case of Loop Antenna
3.6 Radiation Resistance of Loop Antenna
3.7 Directivity of Circular Loop Antenna
3.8 Applications of Loop Antennas
3.9 Salient Features of Loop Antenna
3.10 Loop Antenna as Direction Finder

UNIT 4 : Antenna Arrays

Antenna Arrays: 2 element arrays - Different cases, Principle of pattern multiplication, N element uniform linear arrays Broadside, End fire arrays, EFA with increased directivity, Derivation of heir characteristics and comparison; Concept of scanning arrays. Directivity relations (no derivations). Related problems. Binomial arrays, Effects of uniform and non uniform amplitude distributions,Design relations.

Contents

4.1 Introduction
4.2 Various Forms of Antenna Arrays
4.3 Array of Point Sources
4.4 Two Point Sources with Currents Equal in Magnitude and Phase
4.5 Two Point Sources with Currents Equal in Magnitude but Opposite in Phase
4.6 Two Point Sources with Currents Unequal in Magnitudes and with any Phase
4.7 n Element Uniform Linear Arrays
4.8 Array of n Elements with Equal Spacing and Currents Equal in Magnitude and Phase Broadside Array
4.9 Array of n Elements with Equal Spacing and Currents Equal in Magnitude but with Progressive Phase Shift - End Fire Array
4.10Array of n Elements with Equal Spacing and Currents with Equal Amplitude and
Progressive Phase Shift-End Fire Array with Increased Directivity
4.11 Pattern Multiplication Method
4.12 Binomial Array
4.13 Phased Arrays or Scanning Arrays
4.14 Effect of Uniform and Non-uniform Amplitude Distributions

UNIT 5 :  Non-Resonant Radiators

Introduction, Traveling wave radiators - Basic concepts, Longwire antennas - Field strength calculations and patterns, V-antennas, Rhombic antennas and design relations, Broadband antennas:Helical antennas -Significance, Geometry, Basicproperties; Design considerations for monofilar helical antennas in axial mode and normal modes (Qualitative treatment).

Contents

5.1 Introduction
5.2 Resonant Antenna and Non-Resonant Antenna
5.3 Travelling Wave Antennas
5.4 Long Wire of Harmonic Antenna
5.5 V Antenna
5.6 Inverted V Antenna
5.7 Rhombic Antenna
5.8 Design of Rhombic Antenna
5.9 Log Periodic Antenna
5.10 Log Periodic Dipole Array (LPDA)
5.11 Broadband Antenna- Helical Antenna
5.12 Helical Antenna Structure and Helical Geometry
5.13 Normal or Perpendicular Mode of Radiation
5.14 Axial or End Fire Mode of Radiation
5.15 Salient Features of Helical Antenna
5.16 Applications of Helical Antennas

UNIT 6 : VHE, UHF and Microwave Antenna-l

Arrays with parasitic elements, Yagi - Uda arrays, Folded dipoles and their characteristics.Reflector antennas: Flat sheet and corner reflectors. Paraboloidal reflectors - Geometry, Characteristics, Types of feeds, FID ratio, Spill over, Back lobes, Aperture blocking, Off-set feeds.Cassegrain Ian Feeds.

Contents

6.1 Introduction
6.2 Dipoles with Parasitic Elements
6.3 Yagi-Uda Antenna
6.4 Folded Dipole Antenna
6.5 Introduction to Reflector Antennas
6.6 Plane Reflectors or Flat Sheet Reflectors
6.7 Corner Reflector
6.8 Principle of Parabolic Reflector
6.9 Paraboloid or Paraboloidal Reflector or Microwave Dish
6.10 Patterns of Large Circular Apertures with Uniform illumination

UNIT 7 : VHE, UHF and Microwave Antennas-II

Horn antennas - Types. Optimum horns, Design characteristics of pyramidal horns: Lens antennas -Geometry. Fcatures, Dielectric lenses and zoning, Applications.

Contents

7.1 Introduction to Horn Antennas
7.2 Types of Horn Antennas
7.3 Design Equations of Horn Antennas
7.4 Radiation from Electromagnetic Horn
7.5 Salient Features of Horn Antennas
7.6 Applications of Horn Antennas
7.7 Slot Antenna
7.8 Impedance of a Slot Antenna
7.9 Salient Features of Slot Antenna
7.10 Babinet's Principle and Complementary Antenna
7.11 Introduction to Lens Antenna
7.12 Principle of Lens Antenna
7.13 Feed Systems of Lens Antenna
7.14 Metal Plane Lens Antenna
7.15 Tolerances of Lens Antennas
7.16 Advantages of Lens Antenna
7.17 Disadvantages of Lens Antenna
7.18 Applications of Lens Antennas
7.19 Luneburg and Einstein Lenses

UNIT 8 : Antenna Measurements

Patterns required, Set up, Distance criterion, Directivity and gain measurements (Comparison, Absolute and 3-antenna methods).

Contents

8.1 Introduction
8.2 Need of Antenna Measurements
8.3 Drawbacks in Antenna Measurements
8.4 Methods to Overcome Drawbacks in Measurement of Antenna Parameters
8.5 Important Techniques Useful for Antenna Measurements
8.6 Basic Concept of Antenna Measurement
8.7 Sources of Error in Antenna Measurement
8.8 Antenna Ranges (Measurement Ranges)
8.9 Range Instrumentation
8.10 Measurement of Radiation Pattern
8.11 Measurement of Input Impedance of an Antenna
8.13 Measurement of Phase of an Antenna
8.12 Measurement of Radiation Resistance of an Antenna
8.14 Measurement of Gain of an Antenna
8.15 Measurement of Directivity
8.16 Measurement of Current Distribution
8.17 Measurement of Antenna Efficiency
8.18 Measurement of Antenna Polarization
8.19 Measurement of Noise Figure and Noise Temperature of an Antenna

UNIT 9   : Wave Propagation - I

Concepts of propagation- Frequency ranges and types of propagation. Ground wave propagation - Characteristics, Parameters, Wave til, Flat and spherical earth considerations. Sky wave propagation - Formation of ionospheric layers and their characteristics, Mechanism of reflection and refraction, Critical Frequency, MUF and skip distance - Calculations for flat and spherical earth cases, Optimum frequency, LUHE, Virtual height, ionospheric abnormalities, Ionospheric absorption.

Contents

9.1 Introduction
9.2 Concept of Wave Propagation
9.3 Basic Definition of Wave and Broad Categorization Of Wave
9.4 General Classification of Waves
9.5 Electromagnetic Wave Spectrum and Frequency Ranges
9.6 Modes of Propagation
9.7 Ground Wave Propagation
9.8 Plane Earth or Ground Reflection of Radio Waves
9.9 Field Strength of Ground Wave at a Distance
9.10 Attenuation Characteristics for Ground Wave Propagation
9.11 Space Wave and Surface Wave
9.12 Wave Tilt
9.13 Sky Wave Propagation
9.14 Structure of Atmosphere
9.15 Propagation of Radio Waves through ionosphere
9.16 Effective Dielectric Constant (e) and Conductivity (o) of ionized Region
9.17 Mechanism of Reflection And Refraction of Sky Wave by ionosphere
9.18 Critical Frequency()
9.19 Maximum Usable Frequency (fMUF)
9.20 Optimum Working Frequency (0WE)

UNIT 10 : Wave Propagation -II

Fundamental equation for free-space propagation, Basic transmission loss calculations. Space wave propagation - Mechanism, LOS and radio horizon. Tropospheric wave propagation- Radius of curvature of path, Effective earth 's radius, Effect of earth 's curvature, Field strength calculations, M-curves and duct propagation, Tropospheric scattering.

Contents

10.1 Friis Free Space Equation
10.2 Space Wave Propagation
10.3 Miscellaneous Aspects about Space Wave Propagation
10.4 Radio Horizon - Line of Sight Propagation (LOS)
10.5 Atmospheric Effects on Space Wave Propagation
10.6 Duct Propagation
10.7 Tropospheric Waves
10.8 Tropospheric Scattering
10.9 Multi-Hop Propagation