The current that flows into the antenna structure (two bars) radiate.
So part of the incident field is reradiated by the dipole. It doesn't
matter whether the antenna current is caused by a transmitter or
incident field.

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.

73

Tony I0JX