Telecommunication Engineering, Antenna Types.

1. Antenna Types and
Applications
Rizwan Ahmed Tahir

2. Tentative Topics
• Antenna
• Tower Types
• Antenna Types
• Antenna Coverage
• Antenna Functions
• Antenna Purpose
• Antenna Principles
• Antenna Applications

3. Antenna
An antenna is a device (usually
metallic) for sending or receiving
electromagnetic waves.

4. Tower Types
Rapid Deployment Station (RDS)
Landscape Tower
Camouflage Tower
Processed Tower
Steel Tubular Tower
Guyed Tower
Angle Steel Tower
Single Tube Tower-Monopole Tower
Processed Tower

6. ½ Wave Dipole
¼ Wave Monopole
Antenna Types
E:
H:
E: H:

7. Horn Antennas
Helical
Antennas
Antenna Types

8. Loop Antennas
Microstrip Antennas
Antenna Types

9. Antenna Types
Plate antenna Whip antenna
Cap antenna
Sector antenna
Polyrod antenna
Ceiling Mount

10. Omni & Directional
Antenna
o Omni antenna
In radio communication, an omni antenna
radiates radio wave power uniformly in all
directions in one plane, with the radiated
power decreasing with elevation angle
above or below the plane, dropping to zero
on the antenna's axis.
o Directional antenna
A directional antenna or beam antenna is
an antenna which radiates or receives
greater power in specific directions
allowing for increased performance and
reduced interference from unwanted
sources

11. Yagi-Uda
• Driven element induces currents
in parasitic elements
• When a parasitic element is
slightly longer than /2, the
element acts inductively and
thus as a reflector -- current
phased to reinforce radiation in
the maximum direction and
cancel in the opposite direction
• The director element is slightly
shorter than/2, the element
acts inductively and thus as a
director -- current phased to
reinforce radiation in the
maximum direction and cancel
in the opposite direction
• The elements are separated by ≈
0.25

12. Log-Periodic Antenna
• A log periodic is an extension of the Yagi idea to a
broad-band, perhaps 4 x in wavelength, antenna with a
gain of ≈ 8 dB
• Log periodics are typically used in the HF to UHF bands

13. Parabolic Reflectors
• A parabolic reflector
operates much the
same way a reflecting
telescope does
• Reflections of rays
from the feed point all
contribute in phase to
a plane wave leaving
the antenna along the
antenna bore sight
(axis)
• Typically used at UHF
and higher
frequencies

14. Patch/Panel Antenna
• Radiation is from two “slots” on left and right edges of patch
where slot is region between patch and ground plane
• Length d = /r
1/2 Thickness typically ≈ 0.01 
• The big advantage is conformal, i.e. flat, shape and low weight
• Disadvantages: Low gain, Narrow bandwidth (overcome by fancy
shapes and other heroic efforts), Becomes hard to feed when
complex, e.g. for wide band operation

15. Dipole Antenna
A dipole antenna is a
straight electrical
conductor measuring
1/2 wavelength from
end to end and
connected at the
center to a radio-
frequency (RF) feed
line.

16. Monopole Antenna
A monopole antenna is
a class of radio antenna
consisting of a straight
rod-shaped conductor,
often mounted
perpendicularly over
some type of conductive
surface, called a ground
plane.

17. Isotropic Antenna
An isotropic antenna is an ideal antenna that
radiates its power uniformly in all directions.
There is no actual physical isotropic antenna.
However, an isotropic antenna is often used as a
reference antenna for the antenna gain.
The antenna gain is often specified in dBi, or
decibels over isotropic.
Isotropic radiation has the same intensity
regardless of the direction of measurement, and
an isotropic field exerts the same action
regardless of how the test particle is oriented. It
radiates uniformly in all directions from a point
source sometimes called an isotropic radiator.

18. Antenna Coverage
Coverage provided from
 Villages, cities, forests, deserts
 Seas, air journey, buildings
 Hills, mountains, glaciers
 Underground(basement)
 Colleges, schools, universities

19. Antenna Functions
• Transmission line
– Power transport medium - must avoid
power reflections, otherwise use
matching devices
• Radiator
– Must radiate efficiently – must be of a
size comparable with the half-
wavelength
• Resonator
– Unavoidable - for broadband applications
resonances must be attenuated

20. Antenna Purpose
• Transformation of a guided EM
wave in transmission line
(waveguide) into a freely
propagating EM wave in space
(or vice versa) with specified
directional characteristics
– Transformation from time-
function in one-dimensional
space into time-function in
three dimensional space
– The specific form of the
radiated wave is defined by
the antenna structure and
the environment
Space wave

21. Antenna Principles
• Radiation Resistance
• Antenna Pattern
2
I
P
R rad
rad 
• Directivity and
Gain
• Bandwidth
• Signal-To-Noise
Ratio

22. Antenna Applications
U.S. Navy’s ELF system
• Operates at 76 Hz
• 80 miles of wire
• Penetrates to
underwater subs
• One-way system

23. Antenna Applications
VHF and UHF Antennas
UHF/VHF/FM
Receiving AntennaTransmitting Tower

24. Antenna Applications
Wireless Communications
¼ Wave Helical ¼ Wave 2-in-1
¼ Wave Whip