Re: Antenna Theory Question

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
.

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