William E. Sabin wrote:
Roy Lewallen wrote:

Only at some distance from the antenna. You can create local E/H
ratios of nearly any value (magnitude and phase).

Roy Lewallen, W7EL

W5DXP wrote:


The ratio of the radiated E-field to H-field has no other choice.
If you stuff EM radiation into free space, the ratio of E-field to
H-field is 376.7 ohms. Zero energy is lost from the EM spectrum when
an electron throws off a photon (until that photon is annihilated).




The near field has a reactive component to the impedance. But is it true
that the real part of that complex impedance must be 376.7 ohms resistive?

Bill W0IYH

Not at all. For example, the magnitude of of the wave impedance E/H is
much lower than 377 ohms very close to a small loop, and much higher
than 377 ohms very close to a short dipole. Interestingly, as you move
away from a small loop, the magnitude of E/H actually increases to a
value greater than 377 ohms, then slowly approaches 377 ohms from the
high side as you move even farther away. The opposite happens for a
short dipole -- the E/H ratio drops below 377 ohms some distance away (a
fraction of a wavelength), then increases to 377 ohms as you go farther yet.

Roy Lewallen, W7EL