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
    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!
  2. sirch2

    Well-Known Member

    Jan 21, 2013
    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


    Apr 5, 2008