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Radio waves received at distance <1 wavelength

  1. Apr 3, 2015 #1
    So let's say a radio station sends out AM waves with a wavelenght of like >50m. You are standing with a receiver at a distance of <25m, what happens to the signal? Is it different or the same as if you were standing a longer distance away then 1 wavelenght?

  2. jcsd
  3. Apr 3, 2015 #2


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    without getting into the complexities of near field/far field theory

    the signal will just be stronger closer in and weaker the further out you go

  4. Apr 4, 2015 #3


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    It will depend on your receiver's antenna.
    If the RX antenna couples to the TX antenna it might deliver sufficient energy to destroy the RX.
    It could also distort the radiation pattern of the TX antenna.
  5. Apr 6, 2015 #4
    But it has nothing to do with the fact that rx is closer then 1 wavelength from tx? So you could tune up tx enough to destroy rx even if they are more then 1 wavelength away from each other?
  6. Apr 6, 2015 #5


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    You could tune a RX element with high Q to destroy the RX at some distance from the TX element. But it takes little coupling and no tuning to destroy the RX if you are in the very near field since induced currents in close proximity can be very high.
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