On Wed, 02 Nov 2005 00:26:06 GMT, Cecil Moore wrote:

Jim Kelley wrote:
... what does that have to do with
"coherently summing all the rays by rotating the antenna"? Just wondering.

"Coherently summing" certainly doesn't imply that interference
is only constructive. An antenna is "coherently summing" all
the rays it receives no matter what direction it is pointed.

Has someone got a good definition of coherent.

I thought that it implied "same phase", as in a coherent source is one
where all rays, photons, whatever are in phase. An antenna may well
receive rays from a single source that are not in phase.

If that is the case, what is "coherent summing". Is it trying to refer
to a function that adds components algebraically, ie having regard for
the magnitude and phase?

Why is light a better vehicle for explanation of an antenna that radio
waves?

Owen
--