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JECRC UDML COLLEGE OF ENGINEERINGKUKAS, JAIPUR

SESSION:-2013-14

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APRACTICAL TRAINING PRESENTATION

ON

ANTENNA AND RADIATION PATTERN(ALL INDIA RADIO, JAIPUR)

Submitted to :Nupur NigamAssistant ProfessorECE Department

Presented By :Kailash Chandra Yadav10EUDEC0517th SEMESTER

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CONTENTS

Introduction To A.I.R.Antenna IntroductionType of AntennasRadiation PatternPattern Lobe and Beam WidthAntenna GainAntenna ArrayKey Learning's At TrainingConclusion

INTRODUCTION TO A.I.R.

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All India Radio(AIR) is one of the largest radio networks in the world.

The Bombay station was inaugurated on July 23, 1927, the Kolkata station followed on August 26, 1927.

AIR was established in 1930 and All India Radio,Jaipur was established at 9th April 1955.

The Satellite Earth station was established at 21st March,1944.

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Around 2,75,000 receiving sets were at the time of Independence, now there are about 132 million estimated radio sets in the country.

AIR today having a network of 237 broadcasting centres 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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SERVING FREQUENCIES IN JAIPUR

SERVICE FREQUENCY

CHANNEL

NAME

LOCATION OF TRANSMITTE

RFM 100.3 MHZ

105.6 MHZ

91.1MHZ

93.3MZ

94.5MHZ

95.0MHZ

98.3MHZ

RADIO PINKCITY/

VIVIDH BHARTI

GYANVANI

RADIO CITY

RED FM

MY FM

FM TADKA

RADIO MIRCHI

M.I ROAD,JAIPUR

VAISHALI NAGAR,JAIPUR

MW 1269 KHZ/

1476 KHZ

AKASHVANI, JAIPUR

M.I ROAD,JAIPUR

SW 4910 KHZ/

7325 KHZ

AKASHVANI, JAIPUR

VAISHALI NAGAR,JAIPUR

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Block Diagram Of Transmitter And Receiver

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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

Introduction Of Antenna

Antenna

Yagi Uda Rohmic Horn

AntennaV

AntennaIsotro

picDipol

e

ƛ/2

ƛ/4

Type Of Antennas

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Horn Antenna½ Wave Dipole

¼ Wave Monopole Microstrip Antenna V Antenna

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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

Auxiliaryantenna

Large distance

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Power pattern vs. Field pattern

The power pattern is the calculated and plotted received power |P(θ, ϕ)| at a constant (large) distance from the antenna.

The amplitude field pattern is the calculated and

plotted electric (magnetic) field intensity, |E(θ, ϕ)| or |H(θ, ϕ)| at a constant (large) distance from the antenna.

The power pattern and the field patterns are inter-related: P(θ, ϕ) = (1/)*|E(θ, ϕ)|2 = *|H(θ, ϕ)|2

P = power

E = electrical field component vector

H = magnetic field component vector

= 377 ohm (free-space, plane wave impedance)

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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

Pattern lobe is a portion of the radiation pattern with a local maximum.

Lobes are classified as: 1) Major lobes2) Minor lobes3) Side lobes4) Back lobes

Pattern Lobe

Beam Width

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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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 areaf = carrier frequencyc = speed of light ( 3X108 m/sec.) = carrier wavelength

2

2

2

44

c

AfAG ee

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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

Re

R R

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Antenna Array

Antenna array consists 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 by reducing interference.

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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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A View of 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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KEY LEARNING’S AT TRAINING

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 while 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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THANK YOU.ANY QUERY ?