It appears as if Stirling Westrup <sti@cam.org> wrote:
|Is there anything stopping us from making sheets of rectennae (I gather
|that is a rectifying antenna, but I'm not sure) that were designed to
|pick up wavelengths in the visible spectrum? These would have to be mighty
|small antennae, so we would have to build them with chip fabrication
|techniques or even nanotech, but they should be highly efficient and
|very long lasting solar cells shouldn't they? What technological barriers
|are currently preventing us from trying this out?
The word ``rectennę'' points at the same concept as ``rectifying antennę'' do.
Some humans use the alternative spellings "rectennas" and "antennas", though
(americanisms, I suppose).
Fact: Non-coherent (non-lasered) human visible light scatter more easily
when sent through gas mixtures like the terran atmosphere than do
non-coherent (non-masered) microwaves.
If one sends lasered human visible light instead of masered microwaves through
the terran atmosphere, then:
(a) One would need more power to reach the same throughput (bandwidth).
(b) The antenna (rectenna) size depends on the wave length to some degree.
Therefore, one would need a larger antenna with human visible light
than with masered microwaves.
NOTE: The terran atmosphere absorbs many wavelengths. Would it absorb so
much more of the microwave radiation than of the lasered human visible
light that the above analysis fails to give a result which matches the
real world?
This archive was generated by hypermail 2b29 : Thu Jul 27 2000 - 14:03:07 MDT