2. UNIT I FUNDAMENTALS OF RADIATION 9
Definition of antenna parameters – Gain, Directivity, Effective aperture, Radiation Resistance,
Bandwidth, Beam width, Input Impedance. Matching – Baluns, Polarization mismatch, Antenna
noise temperature, Radiation from oscillating dipole, Half wave dipole, Folded dipole, Yagi array.
UNIT II APERTURE AND SLOT ANTENNAS 9
Radiation from rectangular apertures, Uniform and Tapered aperture, Horn antenna, Reflector
antenna, Aperture blockage, Feeding structures, Slot antennas,Microstrip antennas – Radiation
mechanism – Application,Numerical tool for antenna analysis
UNIT III ANTENNAARRAYS 9
N element linear array, Pattern multiplication, Broadside and End fire array – Concept of Phased
arrays, Adaptive array, Basic principle of antenna Synthesis-Binomial array
UNIT IV SPECIALANTENNAS 9
Principle of frequency independent antennas –Spiral antenna, Helical antenna, Log periodic.
Modern antennas- Reconfigurable antenna, Active antenna, Dielectric antennas, Electronic band
gap structure and applications, Antenna Measurements-Test Ranges, Measurement of Gain,
Radiation pattern, Polarization, VSWR
UNIT V PROPAGATION OF RADIO WAVES 9
Modes of propagation, Structure of atmosphere, Ground wave propagation, Tropospheric
propagation, Duct propagation, Troposcatter propagation, Flat earth and Curved earth concept Sky
wave propagation – Virtual height, critical frequency, Maximum usable frequency – Skip distance,
Fading, Multi hop propagation
3. Course Objectives:
• To enable the students to learn the basic antenna
parameters and radiations from dipole antennas.
• To make the students to understand the various types of
aperture and slot antennas and its radiation mechanism.
• To enable the students to gain knowledge about the
various types of antenna arrays.
• To enable the students to learn the special antennas and
antenna measurements.
• To make the students to understand the different types
of propagation of radio waves at different frequencies.
4. Course Outcomes:
After completion of the course, it is expected that:
The students will be able to
• Analyze the basic antenna parameters and radiations
from dipole antennas.
• Describe the various types of aperture and slot
antennas.
• Explain about the various kinds of antenna arrays.
• Apply the various types of special and modern antennas
based on the applications.
• Analyze the different types of propagation of radio
waves at different frequencies.
5. Definition of antenna
Usually defined as a metallic device for
radiating or receiving radio waves.
Antenna is a transition device or
transducer between a guided wave and a
free space wave or vice versa.
