tomerbr wrote:

this was a qustion from my instractor in college



Ignore the arguing going on here and suffice it to say that you could
get a PhD in antenna theory and spend a lifetime experimenting and just
begin to have a clear understanding of antennas. That may be
exaggerated, but only slightly.

A few general things to keep in mind. Many cell phones work on two
different bands, the antenna needs to work on both. When you are
interested in signals in a certain direction, in this case out and not
up, the longer the antenna the more gain and the more directional it
will be. Don't mistake that as an indication that you just want as long
as a wire as you can get, it is much more complex than that. For an
omni directional antenna where you want to limit the signal to out and
not up, stacking several antennas and hooking them all together in some
fashion, is one way to do that, but I doubt that any of the little cell
phone antennas do that. About the only time you would want an antenna
that also send the signal up is if you are communicating with low earth
orbit satellites that could be anywhere form the horizon to straight
above you. In that case, the antennas start looking more interesting,
that a vertical element.

--
Chris W
KE5GIX

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