Re: NEC-LIST: Re: Plasma Antennas

Here are some details of a commercial plasma steering antenna,
in which the plasma is used as a reflector and not as active
radiating element. The technology is similar to plasma TV
displays; that-is down at the semiconductive elements.
Interesting reading.

http://www.plasmaantennas.com/Howdoesitwork.html
plasma is an ionised gas which, when highly energised, behaves
as a conductor. A plasma antenna generates localised
concentrations of plasma to form a plasma mirror which
deflects an RF beam launched from a central feed located at
the focus of the mirror. An ionised region, or solid state
plasma, can be generated in silicon using electronically
controlled devices (plasma diodes) that are positioned between
closely spaced metal surfaces which constrain the beam.

v/r
Kenneth Carrigan
Electromagnetic Engineer,
Anteon, Systems Engineering Group

>-----Original Message-----
>From: Jim Lux [mailto:James.P.Lux_at_jpl.nasa.gov]
>Sent: Thursday, May 13, 2004 3:48 PM
>To: nec-list_at_gweep.ca
>Subject: Re: NEC-LIST: Re: Plasma Antennas
>
>
>At 09:35 AM 5/12/2004 -0700, Jasper van der Graaff wrote:
>>Plasma antenna technology looks to be very interesting, with
>a number of
>>advantages over normal antennas. There are also other very
>interesting
>>applications for plasma conductors, such as EM shields (Time
>Selective
>>Surfaces?!). However, at the moment it is unclear for me to
>see all the
>>disadvantages. Ofcourse there is the issue with noise,
>however Markland
>>states that there is very little noise after the gas is
>ionised and it
>>does not have to be problematic for transmit antennas. And
>there is the
>>temperature issue, as remarked by Erik, but presumably also
>cost, total
>>system weight (not of the aerial), reliability and
>maintenance are worse
>>than for a simple metal antenna.
>
>The idea of using plasma as a conductive element in an antenna
>is quite
>clever (of course, wasn't that one of the goals of HAARP.. to
>modulate a
>very large ionized cloud in the upper atmosphere to make a reasonably
>efficient ELF radiator?). It's quite difficult to find anything
>substantive on Markland's site (or on logical links from
>there), but this
>is quite characteristic of high-tech companies trying to get
access to
>capital markets. Lots of powerpoint and dazzle, but not much
>substance.
>
>I found no citations in the "Web of Science" for T R Anderson
>where plasma
>or antenna appears in the title.
>
>However, looking through IEEE's search engine, there is a
>paper by T.R.
>Anderson (of Anderson Sci., Inc., with the same email address
>used in one
>of the SBIR proposals) titled
>Electromagnetic noise from frequency driven and transient plasmas
>Anderson, T.R.;
>Electromagnetic Compatibility, 2002 IEEE International Symposium
>on ,Volume: 1 , 19-23 Aug. 2002
>Pages:498 - 501 vol.1
>
>A quick glance over the paper shows that it is relevant to the
>"noise from
>plasma issue".
>
>Another useful citation might be:
>Control of electromagnetic interference from arc and electron
>beam welding
>by controlling the physical parameters in arc or electron beam
>theoretical
>model
>Anderson, T.R.;
>Electromagnetic Compatibility, 2000. IEEE International
Symposium on ,
>Volume: 2 , 21-25 Aug. 2000
>Pages:695 - 698 vol.2
>
>The frequency selective surface ones (only abstracts, from
>what I could find):
>Plasma frequency selective surfaces
>Anderson, T.; Alexeff, I.; Raynolds, J.;
>Plasma Science, 2003. ICOPS 2003. IEEE Conference Record -
>Abstracts. The
>30th International Conference on , 2-5 June 2003
>Pages:237
>Theory and experiments of plasma antenna radiation emitted
>through plasma
>apertures or windows with suppressed back and side lobes
>Anderson, T.; Alexeff, I.;
>Plasma Science, 2002. ICOPS 2002. IEEE Conference Record -
>Abstracts. The
>29th IEEE International Conference on , 26-30 May 2002
>Pages:294
>
>
>>I have retrieved some information on plasma antennas from
the various
>>patents on the subject and from Markland's website. Does
>anyone have more
>>(better) sources in which some of the issues with plasma
antennas are
>>addressed?
>
>
>And of course, just because it's patented doesn't mean it
>works very well,
>or at all, viz. US Patent 6024810 Hyper-light-speed antenna
>(I find the fact that the inventor says that it will improve
>plant growth
>particularly significant)
>
>
>>Also: how mature is the technology at the moment? The pictures on
>>Markland's site show a number of antennas (which presumably
>work?). On the
>>other hand, the technology is still listed under the subject
>"emerging
>>technologies" of their website. Does anyone know if there are
>companies
>>actually offering plasma antennas for sale? Currently most of
>the research
>>and application looks to be US DoD only!
>
>Interesting that Markland doesn't put the reports they
>produced under their
>ONR and SBIR contracts online. They probably don't actually
have them,
>because some quick searching of databases shows that Markland didn't
>actually do the work:
>
>
>For instance, the SBIR contract they cite on their web site
>DASG60-02-C-0055 was awarded to a company called ASI
>Technology Corp, with
>a principal investigator of Theodore Anderson
>ASI does/did a lot of work in Plasma antennae: DASG60-02-P-0033,
>N00178-03-C-1013, etc.
>
>Perhaps Markland Technology has bought/licensed the work of
>Dr. Anderson
>from ASI?
>>I note that the '746 patent gives Anderson as residing in
>>Masachusetts (a
>>long way from Henderson NV, where ASI is based) and also has
>>Igor Alexeff
>>as a co-inventor.
>>
>>Many of Anderson's earlier patents are assigned to the USA,
>usually an
>>indication that the work was done under government contract
>>(perhaps the
>>SBIR and ONR contracts Markland cites on their website?)
>>
>> From a press release of ASI:
>>
>>ASI will be using certain equipment and facilities at the
>>University of
>>Tennessee - Knoxville to support this effort. The principal
>>investigator
>>under the contract is ASI's Theodore Anderson, Ph.D., a plasma
>>physicist
>>and mathematician.
>>
>>Anderson is the inventor of a number of plasma antenna innovations.
>>
>>Jerry Polis, president, stated, "We have performed pioneering plasma
>>science on antennas, communication links and shields. This contract
>>furthers our patent-pending shielding technology for the
>protection of
>>antennas and electronics from interference. This technology has
>>applications in protecting commercial systems as well."
>>
>>-----------
>>
>>As with many things where the technology might have marketable
>>aspects,
>>it's tough to track down the real meat, if there is any...
>>
>>Odd thing of course that Anderson is in NY or MA, but the
>>company is in
>>Henderson NV (Henderson is essentially a suburb near Las
>>Vegas). Perhaps
>>there's better tax treatment, etc.
>>
>>
>>
>>>best regards,
>>>Jasper van der Graaff
>>
>>James Lux, P.E.
>>Spacecraft Telecommunications Section
>>Jet Propulsion Laboratory, Mail Stop 161-213
>>4800 Oak Grove Drive
>>Pasadena CA 91109
>>tel: (818)354-2075
>>fax: (818)393-6875
>>
>>--
>>The NEC-List mailing list <nec-list_at_gweep.ca>
>>http://www.gweep.ca/mailman/listinfo.cgi/nec-list
>>
>

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