G.NARAYANAMMA INSTITUTE OF TECHNOLOGY & SCIENCE(FOR WOMEN)

AUTONOMOUS under JNTUHIII Year B.Tech I Semester L T/P/D C

4 1/-/- 4ANTENNAS & WAVE PROPAGATION

(Common to ECE, ETM)Objectives:To understand how an antenna works, different types of antennas, theirfeatures and the modes of wave propagationUNIT-I: Antenna BasicsAntenna Basics: Introduction. Basic Antenna Parameters - Patterns,Beam Area, Radiation Intensity. Beam Efficiency, Directivity-Gain-Resolution, Antenna Apertures. Effective Height. Illustrative Problems.Fields from Oscillating Dipole. Field Zones. Shape-ImpedanceConsiderations. Antenna Temperature. Front - to-back Ratio. AntennaTheorems. Radiation- Basic Maxwell's Equations, Retarded Potentials -Helmholtz TheoremUNIT-II: Thin Linear Wire AntennasThin Linear Wire Antennas - Radiation from Small Electric Dipole,Quarter Wave Monopole and Half Wave Dipole - Current Distributions.Field Components. Radiated Power, Radiation Resistance, Beam Width,Directivity, Effective Area and Effective Height, Natural CurrentDistributions, Far Fields and Patterns of Thin Linear Centre-fedAntennas of Different Lengths. Illustrative Problems. Loop Antennas -Introduction, Small Loop, Comparison of Far Fields of Small Loop andShort Dipole, Radiation Resistances and Directivities of Small and LargeLoops (Qualitative Treatment).UNIT-III: Antenna Arrays: Point SourcesAntenna Arrays: Point Sources - Definition. Patterns, arrays of 2 IsotropicSources - Different Cases, Principle of Pattern Multiplication, UniformLinear Arrays - Broadside Arrays. End fire Arrays. EFA with IncreasedDirectivity. Derivation of their Characteristics and Comparison. BSAswith Non-uniform Amplitude Distributions - General Considerations andBinomial Arrays. Arrays with Parasitic Elements. Yagi-Uda Array. FoldedDipoles and their Characteristics. Illustrative Prob1ems.UNIT-IV: VHF, UHF and Microwave Antennas and AntennaMeasurements:Helical Antennas - Helical Geometry, Helix Modes, Practical DesignConsiderations for Monofilar Helical Antenna in Axial and Normal Modes.Horn Antennas -Types, Fermat's Principle. Optimum Horns. DesignConsiderations of Pyramidal Horns, Reflector Antennas - Introduction,Flar Sheet and Corner Reflectors. Paraboloidal Reflectors - Geometry,

Pattern Characteristics, Feed Methods, Reflector Types - RelatedFeatures, Lens Antennas - Introduction, Geometry of Non-metallicDielectric Lenses. Zoning, Tolerances, Applications, Micro strip Antennas-Introduction, Features, Advantages and Limitations, Rectangular PatchAntennas - Geometry and Parameters, Characteristics of Micro stripAntennas. Impact of Different Parameters on Characteristics. IllustrativeProblems. : Introduction. Concepts - Reciprocity, Near and Far Fields,Coordinate System, Sources of Errors. Patterns to be Measured, PatternMeasurement Arrangement. Directivity Measurement, GainMeasurements (by Comparison, Absolute and 3-Antenna Methods)UNIT-V: Wave PropagationWave Propagation - I: Introduction, Definitions, Categorizations andGeneral Classifications, Different Modes of Wave Propagation, Ray/ModeConcepts. Ground Wave Propagation (Qualitative Treatment) -Introduction. Plane Earth Reflections, Space and Surface Waves, WaveTilt, Curved Earth Reflections. Space Wave Propagation - Introduction,Field Strength Variation with Distance and Height. Effect of Earth'sCurvature, Absorption. Super Refraction, M-Curves and DuctPropagation, Scattering Phenomena. Tropospheric Propagation, Fadingand Path Loss Calculations.Wave Propagation - II:Sky Wave Propagation - Introduction, Structure of Ionosphere, Refractionand Reflection of Sky Waves by Ionosphere, Ray Path. Critical Frequency,MUF. LET. OF, Virtual Height and Skip Distance, Relation between MUFand Skip Distance. Multi-hop Propagation, Energy Loss in Ionosphere,Summary of Wave Characteristics in Different Frequency Ranges.Outcomes:The students will know different types of antennas, design proceduresand modes of wave propagation.TEXT BOOKS:1. Antennas and Wave Propagation - J.D. Kraus, RJ. Marhefka andAhmad S. Khan. TMH, New Delhi, 4th ed., (Special Indian Edition),2010.

2. Electromagnetic Waves and Radiating Systems - E.C. Jordan and K.G.Bahrain. PHI, 2nd e d., 2000.

REFERENCES:1. Antenna Theory - C.A. Balanis, John Wiley & Sons, 3rd ed.. 2005.2. Antennas and Wave Propagation - K.D. Prasad, Satya Prakashan,

Tech India Publications,New Delhi, 2001.3. Transmission and Propagation - E.V.D. Glazier and H.R.L. Lamont,4. The Services Text book of Radio, vol. 5, Standard Publishers

Distributors, Delhi.5. Electronic and Radio Engineering-EE.Terman,McGraw-Hill,4thedition, 1955.