Thread: Standing waves
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Old September 21st 09, 06:09 PM posted to rec.radio.amateur.antenna
Szczepan Białek Szczepan Białek is offline
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First recorded activity by RadioBanter: May 2009
Posts: 197
Default Standing waves


"Cecil Moore" wrote
...
Richard Fry wrote:
At the top of a monopole, and at the ends
of a dipole the net current is almost zero -- so those locations
generate very little of the total EM radiation from these antennas.


Since the forward current and reflected current are equal
in magnitude and opposite in phase at the ends, they act
like transmission line currents and the magnetic fields
cancel at the ends. They are in phase at the feedpoint -
hence the maximum radiation at that point.


EM means elecro- magnetic. Radiation can start from any of them, See what
Richard Harrison wrote: "At the open circuited ends of a resonant antenna
there is almost double
the forward voltage but zero total current due to cancellation of the
dorward and reflected currents at the open circuit. At the open circuit
in the wire, all the energy in the wave is transferred to the electric
field."
S*