microwave working principle

Can anyone pls explain me the working phenomenon of the microwave dishes shown in the attached file?

Secondly, I would like to know that is there any relation betweed the diameter of microwave dishes and beamwidth?

I mean is it true that the bigger the diameter of microwave dishes lower the beam width ............!

Pls explain?

Thanks

--X--

Hi there,
The basic principle is a RF-feed that illuminates (projects radiation) the dish. The dish reflects the radiation and the whole antenna radiates "outwards".

You can find a simple insight here: http://www.setileague.org/askdr/parabola.htm


P.