Sea based rectena

>
> > Ian,
> >
> > I am not sure I agree with your points.
>
> That cannot be! I am always correct! ;-)
>
> I must eat my words and concede on this occassion :-)
>
> > Not all microwaves are absorbed by water.
>
> All microwaves are absorbed by water, it's just a
> question of degree.
>
> You are right. I could not find any good curves,
> but I learned that all microwaves above 1000 MHz are
> absorbed by
> water, higher frequencies are absorbed even more.
> At Ka band and above it becomes a dominant
> consideration in the system design.

Yeah, what you really want to do is increase the
wavelength, but then the SPS transmitter/receivers
get bigger proportionately because they are sized
by diffraction.

> But its unclear why you would want to do this.
>
> I can see one reason. Floating a rectenna on the
> surface makes it very vulnerable to severe weather,
> the first gale
> or hurricance would probably destryo it. It would ne
> niuce if it could be safely underware, but alas that
> just will not
> work.

As I expect you've spotted in the web page you mentioned
in the other email, sea water doesn't work; the ions conduct
far too well to let any penetration occur to speak of;
the waves hitting the water would be like light hitting a
speckly mirror.

They have to use very long wavelengths for talking to
submarines though- something nutty like 50 hertz or less;

and even then there are depth constraints.