[Barry Goldwater]

Try looking here:
http://en.wikipedia.org/wiki/Rectenna

and here:
http://www.techbriefs.com/content/view/1981/32/

and here:
http://www.nrel.gov/docs/fy03osti/33263.pdf

and here:
http://charon.colorado.edu/Microwave/papers/2000/EuMC_JHnlBP_00.pdf

and here:
http://ieeexplore.ieee.org/Xplore/login.jsp?url=/iel1/2220/6808/00274732.pdf?arnumber=274732

and here:
http://sciencelinks.jp/j-east/article/200017/000020001700A0495811.php

and here:
http://adsabs.harvard.edu/abs/2003AIPC..664..292A

and here:
http://findarticles.com/p/articles/mi_qa3957/is_200008/ai_n8914804

and here:
http://ece.colorado.edu/~pwrelect/Seconddraft/paper_archives/efficientbroadbandrf_apr2005.pdf

The problem in the original article are the rectifier diodes for use at infrared wavelengths, of which the article makes no mention. In metals, such as gold, the extinction length is about 1.5 wavelengths for IR. Semiconductor diodes will not work so other types are needed.

[Outland]

Admittedly, I should have better qualified my statement by relating it to relatively weak sources of energy. Rectennas can output significant amounts of power, but only as long as the source of that power has a high output to begin with (ie: satellite microwave power in the megawatts confined to a narrow radiation pattern or nearby high power microwave sources as in the NASA Microstrip Patch Rectenna article.

By comparison, the Sun's total EM output averages about 1.2kW/m2 at the earth's surface. Compare this with the average 4kW/cm2 of microwave energy used as a source for microwave rectennas with 56% efficiency.. At this rate, all of California would need to be covered in optical rectennas just to power a small part of LA (only 1% efficiency??). Maybe that's not a bad idea on second thought.

[southland]

btt

[monkeyshine]

A rectenna? Hey, I’m all for energy independence but I’ve been told the sun doesn’t shine there... :-)

[southland]

bttt