Alan Peake wrote:


Roy Lewallen wrote:
Alan Peake wrote:


If one were to find lossless material (superconductors?) for the
short antenna and it's corresponding matching network, what would
happen as the antenna became shorter and shorter compared with the
half-wave dipole? Would it simply approach an isotropic radiator?
Alan


No. The answer can be found in any antenna textbook,
...
etc.

Roy Lewallen, W7EL


Thanks Roy. Unfortunately, since I retired, I no longer have access to
Jasik, Kraus etc. So, thanks for the answer. I should have realised that
a dipole of any length is still a dipole and as such will not radiate
off it's ends. Mind you, Eznec shows the average dipole, less than
half-wave above ground, goes pretty close to an isotropic radiator for
all practical purposes
Alan



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You appear to be extrapolating, if I see this correctly, that since all
of the radiation is believed to come from one end of the dipole, then
the rest of the antenna is merely acting as the necessary reactances and
resistance needed to obtain the proper feedpoint impedance at a given
frequency. True?

Following that line of reasoning, if the need for the aggregate
reactances/resistances can be eliminated via superconducting elements,
one will have just a single point source of radiation. Or, what is
commonly known as an isotropic radiator. I suspect that the plasma
antenna fellows are contemplating this too.

Ed, NM2K