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?

No it wouldn't, Cecil. Even you know better than that. For those who
believe Cecil, consider a lossy transmission line terminated in a short,
or open. The signal is attenuated as it goes down the line, and also
attenuated as it comes back up the line, in an exponential fashion.
The envelope is thus not sinusoidal. The signal may be sinusoidal,
but the envelope can't possibly be. Cecil's antennas may be lossless,
but most of us want our antennas to radiate energy, hopefully, as
efficiently as possible, so we have to put up with current distributions
that aren't easy either to envision or to calculate. That's why even
Cecil uses EZNEC.
73,
Tom Donaly, KA6RUH