What sort of loop are you asking about? If it's a small loop (that is,
small in terms of wavelength):

AndyS wrote:
Andy asks

When one uses the equations for a loop antenna to determine what
voltage will be developed at the antenna terminals due to a passing
signal,
is the calculated voltage with the antenna terminated in an open
circuit,
or a resistance equal to the characteristic impedance of the antenna,
or some other load ?

Most likely open circuit. If not, it would be terminated in the complex
conjugate of its impedance as a source, which (for a small loop) will be
a very large impedance consisting of a large amount of inductive
reactance in series with a very small resistance.

I haven't seen any of the texts state specifically whether the
voltage
is open circuit or otherwise....

Same question for any antenna ---- if I use Power Density times
Capture Area , it implies that the antenna is terminated in a
resistive
matched load....but I haven't seen it specifically stated. Perhaps
the
issue is too obvious to write down. But I would like to see it.

Here it would be terminated in the complex conjugate of its impedance,
and the result of your calculation -- power -- would be the power
dissipated in that very small resistance.

The phrase "resistive matched load" you used above is an oxymoron
because of the very large reactance required for a matched load.

I would appreciate some small discussion on this. It is a very
simple
thing to clear up if anyone here has first hand knowledge of the
issue.

Thanks, W4OAH

Roy Lewallen, W7EL