All India Radio (AIR) in Jaipur was established in 1955 and provides radio services across Rajasthan. AIR has a network of broadcasting centers across India that use various antenna types like dipoles, yagis, and arrays to transmit programs. This presentation discussed the history of AIR, described common antenna radiation patterns and lobes, explained how antenna gain and effective area are calculated, and highlighted that antenna arrays can electronically control their radiation patterns. The presenter found the training experience at AIR beneficial for understanding practical communication concepts.

1. 1
A
PRACTICAL TRAINING PRESENTATION
ON
ALL INDIA RADIO(JAIPUR)
Submitted to :
(Training seminar coordinator)
Presented By :
VIKASH JAKHAR
Electronics & Communication

2. 2
CONTENTS
 Introduction
 History and present scenario
 Antenna Introduction
 Radiation Pattern
 Pattern Lobe and Beam Width
 Antenna Gain
 Types of Antenna
 Antenna Array
 Key learning's
 Conclusion

3. INTRODUCTION TO A.I.R
3
 A.I.R is one of the largest radio networks in
the world.
 A national service planned, developed and
operated by the Prasar Bharati Broadcasting
Corporation of India
 All India Radio, Jaipur was established at 9th
April,1955.
 The Satellite Earth station was established at
21st March,1944.


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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.

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 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
transmitters.
 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.

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 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
people.
OBJECTIVE

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SERVICES
SERVICE FREQUENCY CHANNEL
NAME
LOCATION OF
TRANSMITTER
FM 100.3 MHZ
105.6 MHZ
RADIO PINKCITY/
VIVIDH BHARTI
GYANVADNI
M.I ROAD,JAIPUR
MW 1269 KHZ
1476 KHZ
AMER CHANNEL M.I ROAD,JAIPUR
SW 4910 KHZ
7325 KHZ
VAISHALI
NAGAR,JAIPUR

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 Antenna is usually a metallic device (as a rod or a
wire) used for radiating or receiving
electromagnetic waves.
 Transmission - radiates electromagnetic energy into
space
 Reception - collects electromagnetic energy from space
 In two-way communication, the same antenna can
be used for transmission and reception
Antenna Introduction

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Radiation Pattern
 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 /
received.

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Radiation Pattern
There are two types of pattern :
1.POWER PATTERN
2.FIELD PATTERN
Power or
field-strength meter
Antenna
under test
Turntable
Generator
Auxiliary
antenna
Large distance

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Radiation Pattern
 Antenna radiation pattern
is 3-dimensional.
 The 3-D plot of antenna
pattern assumes both
angles θ and ϕ varying,
which is difficult to produce
and to interpret
3-D pattern
3-D pattern

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Radiation Pattern
2-D pattern
 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
pattern’s maximum
Two 2-D patterns

13. 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
Pattern Lobe

14. Pattern Lobes and Beam Widths

15. Beam Width
 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.

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Pattern Lobes and Beam Width

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Antenna Gain
 Antenna gain
 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)
 Effective area
 Related to physical size and shape of antenna

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Antenna Gain
 Relationship between antenna gain and effective
area
G = antenna gain
Ae = effective area
f = carrier frequency
c = speed of light (» 3 ´ 108 m/s)
= carrier wavelength
2
2
2
44
c
AfA
G ee

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Types of Antennas
 Isotropic antenna (idealized)
Radiates power equally in all directions
 Dipole antennas
Half-wave dipole antenna (or Hertz antenna)
Quarter-wave vertical antenna (or Marconi
antenna)

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Types of Antennas
 Yagi
 Phased arrays
 Vertical or Horizontal
 Horns for super ultra
high frequencies
 Mobile antennas

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Radiation Efficiency
 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:
r
r l
R
e
R R

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Antenna Array
 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
coverage area.
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.
.

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Antenna Array
27 antennas along 3 railroad tracks provide baselines
up to 35 km. Radio images are formed by correlating
the signals garnered by each antenna.

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Advantages of Antenna Array
 Possibilities to control electronically
Direction of maximum radiation
Directions (positions) of nulls
Beam-width
Directivity
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.

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KEY LEARNINGS
 Important concepts of communication.
 Resource management.
 Discipline.
 Development of a practical point of view towards
the work.

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CONCLUSION
 It was a wonderful experience , training in A.I.R.
 There is great scope for engineers in the field of
communication.
 Exposure to practical working conditions will be beneficial
for our career.

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QUERIES ???
(if any..)

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Thank u…