all india radio ppt

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all india radio ppt

  1. 1. 1 A PRACTICAL TRAINING PRESENTATION ON ALL INDIA RADIO(JAIPUR) Submitted to : (Training seminar coordinator) Presented By : VIKASH JAKHAR Electronics & Communication
  2. 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. 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. 
  4. 4. 4 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.
  5. 5. 5  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.
  6. 6. 6  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
  7. 7. 7 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
  8. 8. 8  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
  9. 9. 9 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.
  10. 10. 10 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
  11. 11. 11 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
  12. 12. 12 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. 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. 14. Pattern Lobes and Beam Widths
  15. 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.
  16. 16. 16 Pattern Lobes and Beam Width
  17. 17. 17 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
  18. 18. 18 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
  19. 19. 19 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)
  20. 20. 20 Types of Antennas  Yagi  Phased arrays  Vertical or Horizontal  Horns for super ultra high frequencies  Mobile antennas
  21. 21. 21 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
  22. 22. 22 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. .
  23. 23. 23 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.
  24. 24. 24 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.
  25. 25. 25 KEY LEARNINGS  Important concepts of communication.  Resource management.  Discipline.  Development of a practical point of view towards the work.
  26. 26. 26 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.
  27. 27. 27 QUERIES ??? (if any..)
  28. 28. 28 Thank u…

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