ANTENNA & WAVE PROPAGATION

Electromagnetic Radiation and Antenna Fundamentals Review of electromagnetic theory : Vector potential, Solution of wave equation, Retarded case, Hertizian dipole. Antenna characteristics : Radiation pattern, Beam solid angle, Directivity, Gain, Input impedance, Polarization, Bandwidth, Reciprocity, Equivalence of radiation patterns, Equivalence of impedances, Effective aperture, Vector effective length, Antenna temperature. Wire Antennas and Antenna Arrays Wire antennas : Short dipole, Radiation resistance and directivity, Half wave dipole, Monopole, Small loop antennas. Antenna arrays : Linear array and pattern multiplication, Two-element array, Uniform array, Polynomial representation, Array with non-uniform excitation-binomial array. Aperture Antennas Aperture antennas : Magnetic current and its fields, Uniqueness theorem, Field equivalence principle, Duality principle, Method of images, Pattern properties, Slot antenna, Horn antenna, Pyramidal horn antenna, Reflector antenna-Flat reflector, Corner reflector, Common curved reflector shapes, Lens antenna. Special Antennas and Antenna Measurements Special antennas : Long wire, V and Rhombic antenna, Yagi-Uda antenna, Turnstile antenna, Helical antenna- Axial mode helix, Normal mode helix, Biconical antenna, Log periodic dipole array, Spiral antenna, Microstrip patch antennas. Antenna measurements : Radiation pattern measurement, Gain and directivity measurements, Anechoic chamber measurement. Radio Wave Propagation Calculation of great circle distance between any two points on earth, Ground wave propagation, Free-space propagation, Ground reflection, Surface waves, Diffraction, Wave propagation in complex environments, Tropospheric propagation, Tropospheric scatter. Ionospheric propagation : Structure of ionosphere, Sky waves, Skip distance, Virtual height, Critical frequency, MUF, Electrical properties of ionosphere, Effects of earths magnetic fields, Faraday rotation, Whistlers.