On 14 Jun 2004 11:53:37 -0700, (David Harper) wrote:

Thanks! You know any simple phased array configurations
that are easy to mathmatically model?...

In a follow-up to your post Roy, W7EL, suggested modeling
an array with his **FREE** EZNEC demo. I'll second that
motion. EZNEC is well worth learning to use if one is doing
any kind of antenna analysis, even back-of-the-envelope
guesstimates.

Here's what I would do to get a high-gain array with EZNEC:

Place a large number of 1/10-wavelength wires in a row,
end to end, and separated from each other by 1/2 wavelength.
Place a current source in the middle of each, up to the
maximum number allowed by the EZNEC demo version. Set each
current source to 1 amp at zero degrees. Force each wire
to consist of only one segment - this makes the current in
it uniform. Have EZNEC evaluate the pattern in the same
plane as the wires. This is a one-dimensional phased-array.

You can vary the amplitude and phase of the individual
current sources to experiment with beam steering. And you
can change the spacing for the individual elements out to
1 wavelength and beyond to see what that does. It's a lot
of fun to watch what happens.

This should be a relatively easy configuration to write a
far-field expression for if you are so inclined. Math never
was my strong suite, so I'm out of my element and can't give
you much help. (Hey, we're just a bunch of ham-radio operators
here).

Have fun!

Jim, K7JEB