PRACTICAL TRAINING PRESENTATION
ALL INDIA RADIO(JAIPUR)
Submitted to :
(Training seminar coordinator)
Presented By :
Electronics & Communication
History and present scenario
Pattern Lobe and Beam Width
Types of Antenna
INTRODUCTION TO A.I.R
A.I.R is one of the largest radio networks in
A national service planned, developed and
operated by the Prasar Bharati Broadcasting
Corporation of India
All India Radio, Jaipur was established at 9th
The Satellite Earth station was established at
HISTORY AND PRESENT SCENERIO
The first radio program in India was broadcast by the Radio Club
of Mumbai in June 1923 .
In 1926 the private Indian Broadcasting Company (IBC) was
granted permission to operate two radio stations; the Bombay
station was inaugurated on July 23, 1927, the Calcutta station
followed on August 26, 1927.
The introduction of the commercial channel ‘Vividh Bharti’ in
October 1957 increased the interest and popularity of radio.
2,75,000 receiving sets at the time of Independence, now there
are about 132 million estimated radio sets in the country.
AIR today has a network of 237 broadcasting centers with 149
medium frequency (MW), 54 high frequency (SW) and 177 FM
The coverage is 91.85% of the area , serving 99.18% of the
people in the largest democracy of the world.
AIR covers 24 Languages and 146 dialects in home services.
To uphold the unity and integrity of the country and the
values enshrined in the Constitution.
Present a fair and balanced flow of information of national,
regional, local and international interest, including contrasting
views, without advocating any opinion or ideology of its own.
Produce and transit varied programs designed to awaken,
inform, educate, entertain and enrich all sections of the
SERVICE FREQUENCY CHANNEL
FM 100.3 MHZ
MW 1269 KHZ
AMER CHANNEL M.I ROAD,JAIPUR
SW 4910 KHZ
Antenna is usually a metallic device (as a rod or a
wire) used for radiating or receiving
Transmission - radiates electromagnetic energy into
Reception - collects electromagnetic energy from space
In two-way communication, the same antenna can
be used for transmission and reception
The radiation pattern of antenna is a representation
of the distribution of the power radiated from the
antenna or received to the antenna as a function of
direction angles from the antenna.
It is independent on the power flow direction.
It is usually different for different frequencies and
different polarizations of radio wave radiated /
There are two types of pattern :
Antenna radiation pattern
The 3-D plot of antenna
pattern assumes both
angles θ and ϕ varying,
which is difficult to produce
and to interpret
Usually the antenna pattern is
presented as a 2-D plot, with
only one of the direction angles,
θ or ϕ varies.
It is an intersection of the
3-D one with a given plane
usually it is a θ = const. plane or a
ϕ= const. plane that contains the
Two 2-D patterns
Pattern lobe is a portion
of the radiation pattern
with a local maximum.
Lobes are classified as:
1) Major lobes
2) Minor lobes
3) Side lobes
4) Back lobes
Half-power beam width (HPBW) is the
angle between two vectors from the pattern’s
origin to the points of the major lobe where
the radiation intensity is half its maximum
First-null beam width (FNBW) is the angle
between two vectors, originating at the
pattern’s origin and tangent to the main
beam at its base.
A measure of the directionality of an antenna.
Power output, in a particular direction, compared
to that produced in any direction by a perfect
omnidirectional antenna (isotropic antenna)
Related to physical size and shape of antenna
Relationship between antenna gain and effective
G = antenna gain
Ae = effective area
f = carrier frequency
c = speed of light (» 3 ´ 108 m/s)
= carrier wavelength
Types of Antennas
Isotropic antenna (idealized)
Radiates power equally in all directions
Half-wave dipole antenna (or Hertz antenna)
Quarter-wave vertical antenna (or Marconi
Types of Antennas
Vertical or Horizontal
Horns for super ultra
The radiation efficiency e indicates how efficiently
the antenna uses the RF power.
It is the ratio of the power radiated by the antenna
and the total power delivered to the antenna
terminals. In terms of equivalent circuit parameters:
Consist of multiple antennas collaborating to
synthesize radiation characteristics not available
with a single antenna. They are able
to match the radiation pattern to the desired
to change the radiation pattern electronically
through the control of the phase and the amplitude
of the signal fed to each element.
to adapt to changing signal conditions.
to increase transmission capacity by better use of
the radio resources and reducing interference.
27 antennas along 3 railroad tracks provide baselines
up to 35 km. Radio images are formed by correlating
the signals garnered by each antenna.
Advantages of Antenna Array
Possibilities to control electronically
Direction of maximum radiation
Directions (positions) of nulls
Levels of side lobes
Using standard antennas (or antenna collections)
independently of their radiation patterns.
Antenna elements can be distributed along
straight lines, arcs, squares, circles, etc.
Important concepts of communication.
Development of a practical point of view towards
It was a wonderful experience , training in A.I.R.
There is great scope for engineers in the field of
Exposure to practical working conditions will be beneficial
for our career.