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Old May 17th 06, 03:34 PM posted to rec.radio.amateur.antenna
Cecil Moore
 
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Default FIGHT! FIGHT! FIGHT!

Cecil Moore wrote:
Roy Lewallen wrote:
As I pointed out some time ago, the envelope of a standing wave isn't
in general sinusoidally shaped.


Assuming the source signal is sinusoidal, your above assertion
would require non-linearity in the antenna. Since antennas are
generally considered to be linear systems, would you please
explain where the nonlinearity is coming from?


Additional thought: Assuming the source signal is a pure sine
wave, if the standing wave current "isn't in general sinusoidally
shaped", then the antenna would have to be introducing harmonic
radiation that doesn't exist in the source signal. That fact is
easily proved with a Fourier analysis.

I wasn't aware that standing wave antennas cause radiation on
harmonic frequencies. Any standing wave current waveform that
deviates very far from a sinusoid would be illegal.
--
73, Cecil http://www.qsl.net/w5dxp