Parabolic Dish Receiver

Discussion in 'General Electronics Chat' started by Robin Mitchell, Nov 8, 2014.

  1. Robin Mitchell

    Thread Starter Well-Known Member

    Oct 25, 2009
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    200
    Hi all,

    So I have been doing a ton of research into radio astronomy and I think I have each stage figured out except for one part, the feed horn.

    I understand that the dish reflects the incoming radio waves and focuses them onto the feed horn but what I cant seem to figure out is what type of antenna or receiver is on the horn! Is it a loop antenna? Is it a long piece of wire or just some metal? I cant seem to figure this one out because for an antenna to be effective it needs to have a length that is some multiple of the incoming wavelength! So whats up with the feed horn? What is the internal structure?

    All the best and many thanks!
    Robin
     
  2. sirch2

    Well-Known Member

    Jan 21, 2013
    1,008
    351
    I believe the horn is just a wave guide, i.e. an empty rectangular (or possibly circular) tube of a specific size depending on frequency that carries the microwaves down to an antenna (quarter wave vertical I think) . The wave guide helps to ensure that the signal came from the dish rather than elsewhere.
     
  3. bertus

    Administrator

    Apr 5, 2008
    15,648
    2,348
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