On Mon, 18 Oct 2004 21:40:32 -0300, "Bob McBeth"
wrote:
Only if someone can explain the above discrepancy.

It seems apparent that one might arrange an array to exploit the difference
between the flat (far field) incoming wavefront in the receiver mode and the
obviously-curved wavefront (near field) being emitted in the transmit case
to produce significantly different macro performance characteristics.

In other words, playing the film backwards doesn't work.

Does it say I am the walrus?

Hi Bob,

Obviously you've been subjected to a dumbed down attitude in response
to your question.

The fact of the matter is that the receive antenna does not sense a
flat wave approaching it because the antenna distorts the continuum
around it. The antenna and the medium out to several wavelengths is
NOT a characteristic Z of 377 Ohms as seen in an undisturbed field.
I've offered this treatment to Thierry, so it seems it would be useful
for you to observe as well at:
http://home.comcast.net/~kb7qhc/ante...elds/index.htm
with a specific example for a monopole at:
http://home.comcast.net/~kb7qhc/ante...ical/index.htm

As you may observe, the medium surrounding the antenna is anything but
consistent. In effect, the medium and the antenna present an RF lens;
and as you may well appreciate, a lens distorts paths to optimize for
a use. This distortion is like pressing into a bowl of jello, that
medium may have been consistent in the beginning, but with the applied
pressure, the near regions to the disturbance present new surfaces and
densities. Same goes for an antenna - transmitting or receiving.

73's
Richard Clark, KB7QHC