rickman wrote:
On 11/1/2014 1:03 PM, wrote:
gareth wrote:
Ignoring, for the moment, travelling wave antenna, and restricting
discussion to standing wave antennae ...
An antenna is an antenna.
Deep thoughts...
A wave is launched, and radiates SOME of the power, and suffers
both I2R losses and dielectric and permeability losses associated
with creating and collapsing the near field.
Nope, voltage is applied to an antenna causing currents to be created
which in turn cause an electromagnetic field to be created.
As antennas are made of real materials they have a resistance and the
current through that resistance leads to losses.
I thought there were *real* materials with no resistance. Isn't that
what a superconductor is?
Well, to be pendatic, there are no real materials with zero resistance
that can be used to build antennas.
As all the current existing superconductors require a bunch of supporting
equipment to keep them cold, they can't be used for antennas.
If room temperature superconductors are ever invented...
However, those are like a cure for the common cold, practical fusion
power, and peace in the Middle East, all just around the corner for
the past half century or so.
--
Jim Pennino