Antonio Vernucci wrote:
Win,

your explanation is very good and convincing. I believe that most of us
would read with interest some further remarks on what happens in the
case of a shorted element (e.g. a director or a reflector), instead of
the driven element.

In those cases all received energy must be re-radiated, but more details
on that mechanism would be welcome.

The impinging field induces a current on the element. The current
produces a field which radiates. An AC current flowing on a conductor
creates a field regardless of how that current is produced. It doesn't
matter whether the current is due to conduction from a source, by
induction from a field, or any combination of the two -- the field
resulting from the current is exactly the same. Yagis and other
"parasitic" arrays depend entirely on this phenomenon for their operation.

Roy Lewallen, W7EL