Several gentlemen have pointed out that I mistakenly said
the radius of curvature of the transmitted
wavefront gets smaller as the signal emanates from the antenna.
I apologize for the slip.
I should have said the "degree of curvature" instead.
I hope this oversight doesn't interfere too severely with
the concept I was trying to describe.
At any rate, a very interesting thread indeed.
I'd like to add that the ray tracing conceptualization may
not be the best way to think about wave phasing and diffraction
problems. The ray tracing analogy could be an oversimplification
when trying to describe constructive and destructive
interference from phase shifts due to diffraction.
It may be non-productive to think about wave phasing
concepts in the context of the ray analogy.
To me, this question about reciprocity in a non-symmetrical
diffraction environment is not so much about simple concepts such as
"the angle of incidence is equal to the angle of reflection", but is
more about the reconstruction of wave interference patterns due to
diffractions in the local neighborhood of the antenna, and
whether or not those phasing patterns remain constant with
changes in the wave front radius due to non-symmetrical placement of
both antennas relative to the location of the diffracting object.
I suspect the phasing interference patterns are different,
depending on signal direction because of the different geometries of
the wavefront interacting with the diffracting objects in
each case.
Sincerely,
CW-AI4MI
>At the local transmitting antenna, a radio wave is emitted which
> spreads out.
> Were the transmitting antenna an isotropic radiator in free space,
> the wave front would remain spherical in shape as it spreads. In our
> case, the wave still spreads out, not exactly spherical, but
> nonetheless it has a curved wave front, who's radius of curvature generally
> decreases as it moves away from the antenna.
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