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

 

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.

 

Hello,

Would this help a bit?
http://www.antenna-theory.com/antennas/aperture/horn.php

This was found using the following query:
Theory "feed horn"

Bertus