Thread: Standing waves
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Old September 23rd 09, 07:55 PM posted to rec.radio.amateur.antenna
Richard Fry Richard Fry is offline
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First recorded activity by RadioBanter: Jun 2006
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Default Standing waves

On Sep 23, 1:12*pm, Szczepan Białek wrote:

" In 0.05 no currents at all at the *feed point" means, of
course, that the current is very very small.


However small it is, it is still the greatest current value that
exists on that dipole.

RF wrote:
The current distribution in such short dipoles is triangular in form:
highest at the center, and zero at the ends of the dipole arms.


S* answered:
No such oddity in the reality.


No matter how short a dipole antenna is in wavelengths, current is
always zero at the ends of each arm of that dipole.

The current distribution on a thin, wire dipole takes the form of a
sine wave. If the antenna is short, as in this case, then the only
part of the sine that can exist is nearly linear. Hence the
~triangular shape for the total current on the dipole.

Confirm this for yourself using Figure 2-2(b) on page 2-4 of the
following link.

http://books.google.com/books?id=xTS... tenna&f=false

RF