All about Antennas

1. Antennas & their Types
Presented By:
ZAHOOR AHMAD WANI

3.  An Antenna (aerial) is an electrical device which
converts electric energy into radio waves, and vice
versa. It is usually used with a radio transmitter or radio
receiver.
 An antenna is a device used for sending or receiving
Electromagnetic waves.
 An antenna Consists of a Transmitter and a Receiver.

4. A device that converts
sound, light, or electrical
signals into radio,
microwave, or other
electrical signals .

5. An antenna used to convert
electromagnetic waves into
electrical energy.

6.  BANDWIDTH
It specifies the range of frequencies over which its performance does
not suffer due to a poor impedance match.
 GAIN
Gain is a parameter which measures the degree of directivity of the
antenna's radiation pattern.
 EFFECTIVE AREA OR APERTURE
The effective area or effective aperture of a receiving antenna
expresses the portion of the power of a passing electromagnetic
wave .

7.  RADIATION PATTERN
It is typically represented by a three dimensional graph, or polar plots of the
horizontal and vertical cross sections.
 IMPEDANCE
As an electro-magnetic wave travels through the different parts of the
antenna system it may encounter differences in impedance.
 POLARIZATION
The polarization of an antenna is the orientation of the electric field (E-
plane) of the radio wave with respect to the Earth's surface and is
determined by the physical structure of the antenna and by its orientation.
 EFFICIENCY
Efficiency of a transmitting antenna is the ratio of power actually radiated
(in all directions) to the power absorbed by the antenna terminals.
PARAMETERS OFANTENNA

8. There are various types of Antennas and few of them are:
1. YAGI – UDA ANTENNA
2. HELIX ANTENNA
3. PARABOLIC ANTENNA
4. LOOP ANTENNA
5. HORN ANTENNA

9.  Yagi - Uda Antenna consists of:
 A Reflector
 Director and a
 Driven element.
 It is a Unidirectional antenna.
 Frequency range – 300MHz - 3GHz.

11. 1. High gain and good front to back ratio.
2. It has narrow bandwidth.
3. It is fixed frequency device.
4. Greater directivity due to director and reflector.

12.  A conducting wire in the form of screw thread fed by
power source.
 The feed line is connected between the bottom of the
helix and the ground plane.
 Helix antenna is Omni-directional.
 Frequency range – VHF and UHF band.
where > VHF= Very High Frequency
UHF= Ultra High Frequency

14. 1. Satellite Communication.
2. Space communication & space probes.
3. For Telemetry applications.

15.  This is used to convert Spherical wave into Plane wave
 The feed antenna is called primary antenna and reflector
is secondary antenna.
 Frequency range - 3GHz-30GHz
Applications
1. Radar communication.
2. Satellite communication.

17.  A directional-type antenna
consisting of one or more
complete turns of a conductor.
 It determines the direction of
arrival of radio signals.
 Frequency range – 500-1600
KHz.

18. 1. Direction finding of signal propagation.
2. Radio (AM/FM) reception.
3. Long distance point to point
Communication.

19.  Horn antennas are obviously very
directional.
 The shape of the horn determines
if the electric or magnetic fields
are maximized.
 The gain is very high in the
direction of the horn’s axis

20. Thank You…
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