Subject Code:55022 L:3 T/P/D:1 Credits:3 Int. Marks:25 Ext. Marks:75 Total Marks:100
UNIT I: Antenna Basics:
Antenna 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-Impedance Considerations. Antenna Temperature. Front - to-back Ratio. Antenna Theorems. Radiation- Basic Maxwell's Equations, Retarded Potentials -Helmholtz Theorem
UNIT II: Thin Linear Wire Antennas
Thin 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 Current Distributions, Far Fields and Patterns of Thin Linear Centre-fed Antennas of Different Lengths. Illustrative Problems. Loop Antennas - Introduction, Small Loop, Comparison of Far Fields of Small Loop and Short Dipole, Radiation Resistances and Directivities of Small and Large Loops (Qualitative Treatment).
UNIT III: Antenna Arrays: Point Sources
Antenna Arrays: Point Sources - Definition. Patterns, arrays of 2 Isotropic Sources - Different Cases, Principle of Pattern Multiplication, Uniform Linear Arrays - Broadside Arrays. End fire Arrays. EFA with Increased Directivity. Derivation of their Characteristics and Comparison. BSAs with Non-uniform Amplitude Distributions - General Considerations and Binomial Arrays. Illustrative Prob1ems.
UNIT IV: VHF, UHF and Microwave Antennas
VHF, UHF and Microwave Antennas - I : Arrays with Parasitic Elements. Yagi-Uda Array. Folded Dipoles and their Characteristics. Helical Antennas - Helical Geometry, Helix Modes, Practical Design Considerations for Monofilar Helical Antenna in Axial and Normal Modes. Horn Antennas -Types, Fermat's Principle. Optimum Horns. Design Considerations of Pyramidal Horns, Illustrative Problems.
UNIT V: VHF, UHF and Microwave Antennas
VHF, UHF and Microwave Antennas - II: Micro strip Antennas -Introduction, Features, Advantages and Limitations, Rectangular Patch Antennas - Geometry and Parameters, Characteristics of Micro strip Antennas. Impact of Different Parameters on Characteristics. Reflector Antennas - Introduction, Flar Sheet and Corner Reflectors. Paraboloidal Reflectors - Geometry, Pattern Characteristics, Feed Methods, Reflector Types - Related Features, Illustrative Problems.
UNIT VI: Lens Antennas
Lens Antennas - Introduction, Geometry of Non-metallic Dielectric Lenses. Zoning, Tolerances. Applications. Antenna Measurements: Introduction. Concepts - Reciprocity, Near and Far Fields, Coordinate System, Sources of Errors. Patterns to be Measured, Pattern Measurement Arrangement. Directivity Measurement, Gain Measurements (by Comparison, Absolute and 3-Antenna Methods)
UNIT VII: Wave Propagation - I:
Wave Propagation - I: Introduction, Definitions, Categorizations and General Classifications, Different Modes of Wave Propagation, Ray/Mode Concepts. Ground Wave Propagation (Qualitative Treatment) - Introduction. Plane Earth Reflections, Space and Surface Waves, Wave Tilt, Curved Earth Reflections. Space Wave Propagation - Introduction, Field Strength Variation with Distance and Height. Effect of Earth's Curvature, Absorption. Super Refraction, M-Curves and Duct Propagation, Scattering Phenomena. Tropospheric Propagation, Fading and Path Loss Calculations.
UNIT VIII: Wave Propagation - II:
Wave Propagation - II: Sky Wave Propagation - Introduction, Structure of Ionosphere, Refraction and Reflection of Sky Waves by Ionosphere, Ray Path. Critical Frequency, MUF. LET. OF, Virtual Height and Skip Distance, Relation between MUF and Skip Distance. Multi-hop Propagation, Energy Loss in Ionosphere, Summary of Wave Characteristics in Different Frequency Ranges.
TEXT BOOKS:
1. Antennas and Wave Propagation - J.D. Kraus, RJ. Marhefka and Ahmad S. Khan. TMH, New Delhi, 4'h ed., (Special Indian Edition), 2010.
2. Electromagnetic Waves and Radiating Systems - E.C. Jordan and K.G. Bahrain. PHI, 2nd e d., 2000.
REFERENCE BOOKS:
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, The Services Text Book of Radio, vol. 5, Standard Publishers Distributors, Delhi.
4. Electronic and Radio Engineering - EE. Terman, McGraw-Hill, 4th edition, 1955.