Re: NEC-LIST: Low angle radiation?

> Hello Achim,
>
> Since my name came up in Jack Belrose's message, and I have some
> differences with your reply to him, I feel compelled to add my own
> $0.02.
>
 [snip]

> While I agree with your statement that each charge never sees the end
> of the dipole (except) those right at the end, I don't see each charge
> oscillating around some rest position. Consider the standing Q/I wave
> on a dipole. The standing wave is comprised of two
> counter-propagating waves moving at essentially contsant speed; there
> is no oscillating charge associated with the standing wave as a
> result. Thus, there is no significant amount of radiation from
> oscillating charges per se. Whatever radiation comes from a dipole
> between its feedpoint and ends appears instead to come from another
> cause, which I believe to be a partial reflection of the propagating
> waves due to the fact that the wire has a wave impedance that varies
> spatially.

Hold on. Aren't the Q and I out of phase? The Q peaks at the end as
the I goes through a zero. There is transport of charge such that the
ends of the dipole are alternatively +/-q and -/+q. Thus radiation
results. Two charged pith balls (one +q and the other -q), stuck them
to the ends of an insulating stick and twirled it around you'd get
radiation too (it would have higher order multipoles than just dipole
though). No standing wave needed.

-David Fluckiger
Received on Sun Feb 20 2000 - 12:47:16 EST