On 3/6/2012 10:49 AM, Bill Horne wrote:
I came across this story today, and I'd appreciate hearing other hams'
opinions as to whether this is possible. TIA.

Bill, W1AC
- - - - -

Pasta-inspired radio waves could unclog the wireless world

Agence France-Presse
6:39 am | Saturday, March 3rd, 2012

WASHINGTON—Radio waves that move like pasta spirals could help unclog
the wireless world by boosting the power of radio communications,
Italian and Swedish researchers said Friday.

The new way to make radio signals more potent without boosting bandwidth
is described in the Institute of Physics and German Physical Society’s
New Journal of Physics edition of March 2.

“In a three-dimensional perspective, this phase twist looks like a
fusillli-pasta-shaped beam,” lead study author Fabrizio Tamburini was
quoted as telling the science website PhysOrg.

“Each of these twisted beams can be independently generated, propagated
and detected even in the very same frequency band, behaving as
independent communication channels.”

That means they do not move linearly like all current forms of radio
communications do, and they do not need more bandwidth to increase their
transmission capacity.

http://technology.inquirer.net/8897/...wireless-world


Sounds like circular polarization to me, Sat-TV uses it to put not one
but TWO transponders on the same frequency.

You can do the same between two FIXED sites using cross polarization,
however in the real world that does not work as well as circular... I
know, I've done it.

--
Nothing adds Excitement like something that is none of your business.
Remove the invalid part to email me.

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In John Davis writes:

On 3/6/2012 10:49 AM, Bill Horne wrote:
I came across this story today, and I'd appreciate hearing other hams'
opinions as to whether this is possible. TIA.

Bill, W1AC
- - - - -

Pasta-inspired radio waves could unclog the wireless world

Agence France-Presse
6:39 am | Saturday, March 3rd, 2012

WASHINGTON—Radio waves that move like pasta spirals could help unclog
the wireless world by boosting the power of radio communications,
Italian and Swedish researchers said Friday.

The new way to make radio signals more potent without boosting bandwidth
is described in the Institute of Physics and German Physical Society’s
New Journal of Physics edition of March 2.

“In a three-dimensional perspective, this phase twist looks like a
fusillli-pasta-shaped beam,” lead study author Fabrizio Tamburini was
quoted as telling the science website PhysOrg.

“Each of these twisted beams can be independently generated, propagated
and detected even in the very same frequency band, behaving as
independent communication channels.”

That means they do not move linearly like all current forms of radio
communications do, and they do not need more bandwidth to increase their
transmission capacity.

http://technology.inquirer.net/8897/...wireless-world


Sounds like circular polarization to me, Sat-TV uses it to put not one
but TWO transponders on the same frequency.

You can do the same between two FIXED sites using cross polarization,
however in the real world that does not work as well as circular... I
know, I've done it.

--
Nothing adds Excitement like something that is none of your business.
Remove the invalid part to email me.


It's not circular polarization, rather, it's another characteristic of
an electromagnetic wave that is being exploited, Orbital Angular
Momentum (OAM). Circular polarization uses spinning (helical)
polarization E & M vectors. This proposed technology would use a
helical wavefront by introducing a time-delay (or phase) distribution of
components of the signal from a dish or array.

I read the latest paper and watched the video abstract at the following link:

http://iopscience.iop.org/1367-2630/14/3/033001/article

but can't say that I completely understand it. The clearest description
of modulation and frequency reuse of OAM that I found appears to be this
article in New Scientist from 2009, including its use in HAARP:

http://www.newscientist.com/article/...-airwaves.html

Quote from the above article:

"The twists remain coherent across vast distances - light years, even
- and can store information in the form of digital bits (1s and 0s),
encoded into the pitch of the twist."

The discussion at this link may also help illuminate the subject better:

http://www.physorg.com/news/2012-03-...io-venice.html

The latest discovery wasn't the theory itself, but rather a practical
demonstration at radio frequencies. OAM is well-known in quantum
mechanics, as well as in electromagnetic radiation at optical
frequencies in the field of astronomy.

- --
73, Paul W. Schleck, K3FU

http://www.novia.net/~pschleck/
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