How is radio frequency can be made short range and long range?

Discussion in 'Wireless & RF Design' started by dante_clericuzzio, Oct 16, 2017.

  1. dante_clericuzzio

    Thread Starter Member

    Mar 28, 2016
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    What is the basic components or part that make radio frequency into short range or long range?
     
  2. Papabravo

    Expert

    Feb 24, 2006
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    Range has very little to do with components and everything to do with frequency. Generally speaking the higher the frequency, the shorter the range. There is also a diurnal variation in range depending on the position of the sun and the conditions in the upper atmosphere. There is also the 11 year sunspot cycle and our present position in that cycle. It is possible to adjust range slightly by increasing or decreasing the radiated power of the output. This is the last thing you do after everything else has been tried.
     
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  3. dante_clericuzzio

    Thread Starter Member

    Mar 28, 2016
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    Ok its the frenquency ...how far in radius is the 4G (2.6 Ghz) can transmit (i meant generally)? Can it be like 50 Km? or at least 20 Km
     
  4. Papabravo

    Expert

    Feb 24, 2006
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    At that frequency the transmission distance is basically line of sight. Another thing that will have an effect on the distance is atmospheric moisture, since water molecules absorb and scatter microwave frequencies.

    You should have found this basic article on propagation:
    https://en.wikipedia.org/wiki/Radio_propagation
     
  5. MrChips

    Moderator

    Oct 2, 2009
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    It depends on the transmitted power, gain and radiation pattern of the transmitter antenna, gain and radiation pattern of the receiving antenna.
     
  6. Motanache

    Member

    Mar 2, 2015
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    It's weird. But the maximum distance at 2G, 3G.....is not due to transmit power(5W) or sensitivity of reception(-109dBm).........
    It is given by the time advance variable.

    At a simple communication depends on the emission power, transmitter bandwidth (Eg SSB) sensitivity of reception and propagation conditions.
     
    Last edited: Oct 20, 2017
  7. nsaspook

    AAC Fanatic!

    Aug 27, 2009
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    True, the signal can be transmitted much longer distances (low earth orbit intercepts of cell signals) but the 4G TDMA technology networking is limited by the speed of light and the need to have round-trip timed slots for users.
     
  8. bertus

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