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Old November 29th 05, 07:31 PM posted to rec.radio.amateur.antenna
Roy Lewallen
 
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Default Antenna reception theory

Richard Harrison wrote:
Roy, W7EL wrote:
"But, if the antenna conductor were perfect, no E field at all could
exist at the wire surface regardless of the magnitude of the E field of
the oncoming wave."

If we have a non-varying E field, a perfect conductor in the field would
have the same voltage everywhere due to the short-circuit connecting all
points.

But, an electromagnetic wave sweeping the wire has an alternating
electric field. Its phase is uniform (the same) across the wavefront
because all points are equidistant from the source. A wire parallel to
the E vector would simultaneously experience the same E field force
throughout its length. "No E field at all could exist at the wire
surface regardless of the magnitude of the E field of the oncoming
wave,"

Why must the wire be perfect?


A time-varying E field can exist in a non-perfect conductor; it cannot
exist in a perfect conductor. You can find the explanation for why this
is in any electromagnetics text.

Roy Lewallen, W7EL