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Wireless Networking Security Hardware

Gas Plasma Antennas Help Wi-Fi Security 163

Posted by michael from the hearsay dept.
mindless4210 writes "Markland Technologies has developed a new gas plasma antenna technology which could help to secure wireless networks. The technology allows for highly directive and electronically steerable digital data transmission via solid-state semi conductor based plasma generators. A plasma antenna can reposition itself at very high speeds, as well as change it's beamwidth and bandwidth, creating spatial and spectral security features which are not presently available with conventional WiFi antenna technology."
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Gas Plasma Antennas Help Wi-Fi Security More

Gas Plasma Antennas Help Wi-Fi Security

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  • Now you see it...... (Score:5, Informative)

    by erick99 ( 743982 ) * <homerun@gmail.com> on Tuesday May 04, 2004 @06:12PM (#9057241)
    This is a very cool technology. This antenna essentially "disappears" when it is not being used, making it fairly "stealthy". And, while a traditional metal rod or dish antenna is "cut" to a specific or very narrow range of frequencies, it would appear that the gas plasma antenna can essentially reconfigure itself to rapidly change frequencies. As a ham radio operator, I can really appreciate how useful that could be.

    Happy Trails!

    Erick

    • My brain hurts (Score:1)

      by Anonymous Coward
      So which is the solid-state part? I'm picuring a generator that creates the plasma antenna beam...close?

    • Re:Now you see it...... (Score:2, Funny)

      by Anonymous Coward
      This antenna essentially "disappears"

      And so will the VC money.

    • Re:Now you see it...... (Score:5, Insightful)

      by nacturation ( 646836 ) <nacturation AT gmail DOT com> on Tuesday May 04, 2004 @06:18PM (#9057312) Journal
      Queue up the "bah! security through obscurity never works" posts. :)

      I agree though, this is really fricking cool. With the right controls, you could make it so that the antenna characteristics change over time according to a pattern known only to those posessing the corresponding private key. Interception is harder and, even if it is intercepted, you could theoretically use this as one additional encryption layer.
      • I can see the "Post Anonymously" option, but where do I find the "Post Humously" option?

        Why? Is there Slashdot after death?

      • It's only cool if your head isn't in the beam (Score:1, Funny)

        by Anonymous Coward
        While it's got some cool aspects to it, the big drawback here is you'll never know if your office is somehow in the line of fire.

        Hmmm. Of course, that could be useful to some nefarious people. Like setting one up so that the antenna points at your PHB and doses him with constant microwave radiation for 8 hours a day.

        This could take the military concept of "fragging" to a new level (not that I'm suggesting such of course).
      • They mention stealth while "not in use", yet, while in use... Plasma sources can be, XENON, ARGON, NEON... All of which are REALLY BRIGHT. For "stealth" that would be useless.

        Holy shit, sir. Did you see that bright bluish light over there, it lasted for 5 seconds then blinked out. I must have been seeing things.

    • So how do you steer it??? (Score:4, Funny)

      by EmbeddedJanitor ( 597831 ) on Tuesday May 04, 2004 @06:26PM (#9057373)
      If it is steerable, then it needs some idea of the direction to steer to. This could be done in a location-based way (eg. GPS) or by tracking signal strengths etc. But basically it means that to use this you will be giving away some idea of your position. It will be like the finger of God pointing at you: "There's the bloke viewing pron".
      • Forget that, remember the wifi locator bracelets they're giving to kids in legoland? Using these things you could pinpoint your kid's exact location.

        Would also work if you compared triangulation data of two of these against a map of wireless authorized zones, then just send security after every client not in an approved zone.
      • > It will be like the finger of God pointing at
        > you: "There's the bloke viewing pron".

        And since when did God get upset a having somebody admire the perfect breasts of his creation?

      • You're emitting radiation in every direction around you when you use standard wireless gear. If this antenna puts out a relatively tight beam, then the observer would have to actually be in the beam's path to detect it, and that still only reduces your location to anywhere on a line instead of anywhere in an area.
    • This antenna essentially "disappears" when it is not being used, making it fairly "stealthy"

      More than just disappear when not in use, it could potentially disrupt snopper while in use. While locked on to a legitimate user, the antenna could change the beam pattern in other directions to disrupt snoopers. Only a snooper that is roughly in the line from antenna to legitimate user would be able to get a consistent signal.
    • It certainly seems like a cool technology, but I'm not sure how it would apply to WiFi - or even Ham for that matter. Yes, a tight beam antenna will provide some slight level of added security (while not substituting for encryption) there is the issue of power requirement - you need to create that plasma - fuel requirement - the gas you're ionizing - and the shielding requirements. The first one is a killer for portable devices (the usual application for this technology - if you're running a desktop, wire
      • It certainly seems like a cool technology, but I'm not sure how it would apply to WiFi - or even Ham for that matter. Yes, a tight beam antenna will provide some slight level of added security (while not substituting for encryption)

        Well, I think it's a bit better than that- a base station with this technology can probably work out the distance as well as the angle- the antenna forms a spatially distributed antenna and hence can measure the phase and intensity and show where the user is.

        there is the issu

        • Well, I think it's a bit better than that- a base station with this technology can probably work out the distance as well as the angle- the antenna forms a spatially distributed antenna and hence can measure the phase and intensity and show where the user is.

          Base stations would be the logical place to use these things, yes, but how is it going to work out the range? You can get a line of position from your phased array, but that alone won't give you a range. You could, I suppose, ballpark it from relati
          • Base stations would be the logical place to use these things, yes, but how is it going to work out the range?

            If you think about it, the wavefront from the trasnmitter has to hit the different parts of the antenna at the 'right' time- it's critically phase dependent- the wavelength of 2.5Ghz is about 15cm, so you can measure the distance to within a fraction of that.

            Basically the bigger the antenna is, the further away you can distinguish the distance. In a fairly real sense you are doing triangulation/t

            • If you think about it, the wavefront from the trasnmitter has to hit the different parts of the antenna at the 'right' time- it's critically phase dependent- the wavelength of 2.5Ghz is about 15cm, so you can measure the distance to within a fraction of that.

              Yes, sort of, that's how we can use a phased array to get a line of position. We have several physical antennas in an array and can calculate the direction of an incomming signal based on the phase difference between the antennas. You can see an exa
              • It's a reflective diffraction grating you can change on the fly. It de/reflects the signal back into a detector. It's not particularly exotic.

                It's decidedly more exotic than the 18 element Yagi I've used for 2.4 gig work, or the 5 element phased array I've used fox hunting.

                You still seem to be missing the point- this system is electronically steerable. Sure there are other ways to do that with switchable antennas, or physical steering, but this is another way.

                This technique does not give a range. Only

                • You still seem to be missing the point- this system is electronically steerable. Sure there are other ways to do that with switchable antennas, or physical steering, but this is another way.

                  No, no. I got the point. You're missing mine - that an electronically steerable plasma grating is more exotic than a conventional antenna array.

                  Didn't say it wasn't cool or wouldn't work. I said it's hungry in both computing power and energy consumption, and simpler solutions exist.

                  It's cool, but it's not especial
                  • That gives you a bearing, yes. The larger the aperature of your array, the more accurate your bearing will be. Unless your array is large enough (and has enough elements) to get multiple relative bearings on the same source, you're not going to get a range simply from the signal's phase.

                    That's not correct. The analogy is not exact, but that's approximately the way GPS works.

                    It's just like focusing in the optical domain- you can focus a phased array a fixed distance away, rather than at infinity.

                    You se

                    • We're at least still somewhat on-topic, and this is certainly an interesting conversation.

                      That's not correct. The analogy is not exact, but that's approximately the way GPS works.

                      Well, actually, if you look at what I said, it is correct. You're not going to get range from the phase. GPS works (horribly over-simplified here, obviously) with each satellite in the constellation saying "I am here now" and the receiver being able to work out the trig based on the time and location for each bird it's watchi
                    • Unencrypted wireless is insecure.

                      Well, you're assuming that wired is secure- unless you're using Tempest shielding evesdropping is reasonably easy even with wired.

                      Basically security isn't all or nothing, ever.

                      In this case, forbidding/ignoring traffic from outside a configured physical perimeter would indeed result in more security for the network in many cases- it prevents people from injecting traffic to your network as well as improving throughput.

                      it should be marginally more efficient - and more

                    • Well, you're assuming that wired is secure- unless you're using Tempest shielding evesdropping is reasonably easy even with wired.

                      I assume only that wired is inherently more secure than wireless. Wireless interception requires no physical access and is trivial to do remotely.

                      Tempest monitoring is non-trivial these days. With the level of emissions dropping lower and lower from modern computer systems, the sensitivity and signal processing power required to to electronic eavesdropping is getting higher
                    • This calculation has nothing to do with phase. It's only the signal strength that matters here.

                      Utter coddswallop. Neither the receive, nor transmit function works unless you have correct phase shift at each emitter. That's the whole point of a phased array. That's where the name "phased element array" comes from. If you have no phase shift then your antenna will work extremely poorly if at all.

                      No, it has become clear to me that you fundamentally don't understand phased arrays in general.

                      I've actually (i

                    • *ROTFLU!*

                      Utter coddswallop. Neither the receive, nor transmit function works unless you have correct phase shift at each emitter. That's the whole point of a phased array. That's where the name "phased element array" comes from. If you have no phase shift then your antenna will work extremely poorly if at all.

                      You know, most of the antennas I've built, including the phased array for fox hunting, work quite well. Transmit and receive functions don't work without proper phase shift? Really? Amazing. So
                    • You know, most of the antennas I've built, including the phased array for fox hunting, work quite well.

                      Yes, I expect it was fixed phase shift, which is correct for that- for a physically steered antenna. That says nothing about the general case of phased element array, which includes active elements with electronic phase shifting; the plasma reflector is an example of that. That's how you can arrange for electronic streering.

                      But neither of them are securing the wireless part of your network.

                      Correct! I

                    • Yes, I expect it was fixed phase shift, which is correct for that- for a physically steered antenna. That says nothing about the general case of phased element array, which includes active elements with electronic phase shifting; the plasma reflector is an example of that. That's how you can arrange for electronic streering.

                      Actually, no, but it was designed for mobile operation since I can get better results with other systems.

                      And which is it? Is the plasma antenna a reflector or a phased array? They'r
    • A whip antenna (or rod as you call it) as you say is tuned to a specific frequency which relate to the standing wave that is generated at the resonant frequency of the antenna. However a parabolic antenna (or dish as you call it) is based on simple geometric optics and is entirely frequency independent (upto certain limits). It is the feed of a parabolic antenna that is frequency dependent, and I've personally been involved in design groups working on feeds covering 5 to 10 octaves of bandwidth.

      D.

  • Sounds great. (Score:5, Funny)

    by Anonymous Coward on Tuesday May 04, 2004 @06:13PM (#9057258)
    In fact it sounds too good to be true.

    Oh wait. I see. It's a press release from a startup company. Never mind.
    • Yeah, and the bastards even patented it. Damn those evil patents... and for such a trivial idea as plasma + modulation = antenna!
    • Oh I see, so all start ups fail, all ideas that sound wonderful must be false.

      There's a huge difference between healthy skepticism and brain dead cynicism.

      Maybe it makes no difference to you, but knowing abount new technologies that have the potential to be an inflection point for multiple device technologies is something that I at least want to be aware of.

  • If you reconfigure the modulators (Score:5, Funny)

    by Neil Blender ( 555885 ) <neilblender@gmail.com> on Tuesday May 04, 2004 @06:14PM (#9057260)
    And verify the heisenberg compensators, it could just possibly work. You might need to check out the lateral sensor array though.
  • Hello, high voltage. It's one thing to put "phased array" antennas on naval vessels, but entirely another to put them in a house. Not to mention the voltage difference needed to generate the plasma.

    Fluorescent bulbs use this sort of principle, too - surely our new gas-plasma antennas aren't to be made of glass?

    Hrm. Perhaps they are.

  • They forgot the best feature of all (Score:5, Funny)

    by nizo ( 81281 ) on Tuesday May 04, 2004 @06:15PM (#9057268) Homepage Journal
    The entertainment value when someone walks up and says, "hey whats this thing..." followed by screams as their hand disappears after touching the new flashy glowing thingy.

  • creating spatial and spectral security features (Score:4, Funny)

    by FreeLinux ( 555387 ) on Tuesday May 04, 2004 @06:15PM (#9057273)
    My BS alarm just tripped and I can't seem to stop it.

  • Directional arials... (Score:2, Insightful)

    by jd ( 1658 )
    ...are nothing new. What is new is that this is a "virtual" arial. IMHO, this has wide-ranging applications. For a start, virtual radio telescopes could be of practically unlimited size, by this arrangement. No physical surface to mess up on.

    • Re:Directional arials... (Score:4, Informative)

      by pclminion ( 145572 ) on Tuesday May 04, 2004 @06:29PM (#9057405)
      Why do you say "virtual?" The antenna is just as real as a metal wire, the only difference is that the positive charges in a plasma are free to move, whereas in a metal the positive charges are locked in the lattice.

      Just because it's not a solid doesn't make it spooky or virtual...

      virtual radio telescopes could be of practically unlimited size, by this arrangement.

      Not really, since the plasma has to be kept "hot" and at low pressures in order to prevent it from recombining back into "normal" uncharged matter again. A device capable of maintaining such a large plasma would require enormous amounts of power and maintainence.

    • With the high speed directional capabilities it claims to have, you could set two of these up at a known distance apart and use them to quickly triangulate every wi-fi client within range.
      That would be one hell of a security measure, alerting security to the exact location of every wi-fi client not in a known approved area.
      • Wouldn't you need three of them to triangulate? Having just two scanners would still leave you with two possible locations.
        • Damn I'm stupid, you could do it with a single unit since it's a fast moving, directional antenna; it's only with omni-directional antennas that you need to triangulate. Although a good system would have an omni-directional antenna scanning for clients, and when it detects one it give the gas-plasma antenna the range at which it found the client, and then the gas-plasma antenna can do a quick search of that area.

    • Plasma antennas... (Score:1, Informative)

      by Anonymous Coward
      are also nothing new. This company's been around for some time doing similar stuff [plasmaantennas.com].

  • Access points (Score:2, Interesting)

    by kinzillah ( 662884 )
    This is a great idea if it works. But if its all directional, how would you have an access point serving many clients? Unless the access point used (an) omnidirectional antenna(s), there would need to be multitudes of these to track each client.

  • Markland Technologies (Score:5, Interesting)

    by metlin ( 258108 ) * on Tuesday May 04, 2004 @06:16PM (#9057288) Journal
    Who the hell are these guys?

    Their other products in the emerging technologies section include Acoustic Core [marklandtech.com] - detecting illicit materials using their acoustic signatures, Vapour Trace [marklandtech.com] - a way to search cargo for contraband materials and Crypto.Com [marklandtech.com] - a double cipher keyless transmission system.

    Thats a lot of cool science and technology for a relatively unheard of company, not to mention their technologies in the Border Security and Chemical Detection systems.

    I had read a while back [usatoday.com] about the CIA and US Govt investing in startups - I think its quite possible that these guys are probably funded thus :)

    Kinda cool yet spooky.

    • I had read a while back about the CIA and US Govt investing in startups - I think its quite possible that these guys are probably funded thus :)

      In-Q-Tel [in-q-tel.com] makes no secret of the companies it invests in [in-q-tel.com], though they are very careful with their money and perform a lot of due-diligence before making any investment. And to be pedantic, In-Q-Tel is not a Governmental agency, they just happen to concentrate their activity based on the needs of the Defense-Intelligence community. The company I work for [basistech.com] is one o

      • Ah, thank you.

        I was somehow under the impression that they would not really make their investments public, but I see no reason why they should not, so it makes sense.

        I was not aware that In-Q-Tel was a seperate entity in itself, I always thought of it as being an arm of the CIA.

        There are lots of programs in the Department of Defence that companies can apply to in order to get research money: you just need to know which back to scratch and get yourself noticed.

        Just out of curiosity, any that you can th
    • Who the hell are these guys?

      They don't appear to have any crypto experts on their management team.

      They seem to be trying (and failing) to register Matt Blaze's long-standing crypto.com url as a trademark [uspto.gov]. They use crypto.com in their documentation as if they owned the url. I don't see a link between Blaze and Markland, but perhaps there is one, although Markland seems to have picked up the Crypto.Com from their subsidiary ERGO Systems, which has been involved in port security for Homeland Security.

    • Thanks for pointing out their other stuff. IMHO it discredits them. The Vapour Trace technology certainly isn't new, and I doubt that Acoustic Core could compete with the scanners that are already out there. As for a keyless cipher, I don't see how you could do cryptography without keys except if it's quantum cryptography or something like that. Security thorough obscurity?
      • Actually, their core contribution the Vapour Trace seems to be the development of some inhouse automatic sensors, embedded into polymer-like material.

        They have a powerpoint on their Vapour Trace site that talks about how they have developed a new polymer that can detect contraband, while the material itself can be queried using RF signals.

        I have not checked, but they seem to project this as a major step in vapour trace technology, and they may quite possibly have some patents to this end - I'm assuming, o

  • I can see it now (Score:5, Funny)

    by MilkmanIAC ( 756513 ) on Tuesday May 04, 2004 @06:17PM (#9057296)
    Picture of a wide-eyed 'generic business person" with big print on the billboard that reads "Got Gas? If not, you're wireless network isn't secure."

  • I can generate my own gas plasma antenna... (Score:1, Funny)

    by Anonymous Coward
    ...if I eat enough Pringles.
  • What good is a directional beam if it hits some radio-reflective object and bounces somewhere else? Also, even if the beam is 99% directional, sensitive or very close receivers could still pick up the 1% that leaks. A security system that is 99% effective is not much better than a system which is 10% effective. Without solid encryption and authentication built-in to the protocol, directional broadcasting is useless. With solid encryption and authentication built-in to the protocol, directional broadcasting doesn't add anything.

    The one place where this could have some good security uses is for undetectable transmission, which is probably interesting to the military.

    Of course, directional broadcasting has a whole set of real benefits, such as getting more bandwidth by allowing more transmitters in the same region, minimizing interference, minimizing radiation output, etc. But to call this a security feature? I guess the "everything good is a security feature" is the parallel to "everything bad is terrorist" idea which seems popular lately.

    -----------
    Create a WAP [chiralsoftware.net] server

    • I agree that touting this primarily as a security feature is the wrong approach. Yes, it is a bit "better" than omni, but the real benefit is "getting more bandwidth by allowing more transmitters in the same region, minimizing interference, minimizing radiation output, etc."

      The thing that is exciting about this is the field of research that it opens up. Of course, directional comm antennas have been around for quite some time, but building networks out of them is relatively new. Do a literature search

    • Try again (Score:2, Interesting)

      by Anonymous Coward
      Having directional or narrow beam capabilities is of tremendous advantage ( not that this capability does not already exist to some extent, but this looks to be an improvement) :

      1. You mentioned the problem of objects in the way, especially reflective ones. For transmission in both cities and non flat terrain, the path of radio signals to the recever frequently travel along paths that include reflections as opposed to straight from the transmitter. This is not changed by the directional signal; the transmi
  • According to their site [marklandtech.com], plasma antennas are interesting for short-pulse applications, such as radar, IFF... Wifi is not mentioned, just a vague "high speed data communications" after a wealth of military applications.

  • Vaporware (Score:5, Insightful)

    by Wise Dragon ( 71071 ) on Tuesday May 04, 2004 @06:20PM (#9057336) Homepage
    So aside from being, literally, vaporware (laugh here, serious point next.), how does this technology compete with phased array systems such as those by Vivato [vivato.net]? I understand the value of phased arrays are that they can focus the output into an extremely narrow beam and send it to just the right place. I Am Not A Physicist, but it seems like solid state electronics are a *little* bit simpler than plasma to work with!

    And safer.

    • Re:Vaporware (Score:4, Informative)

      by Tlosk ( 761023 ) on Tuesday May 04, 2004 @06:48PM (#9057582)
      Because of the speed with which they can revert to nonplasma state they can prevent ringing and other artifacts inherent to metal antennae, increasing the fidelity and reliability as well as the signal processing logic on the receiving end.

      There's also the weight and size issue, with the plasma coming in both lighter and smaller to an equivalent conventional one.

      But you're right of course that it will be a while or perhaps never that it will be just as easy or easier to work with plasma. So you might not see one on a $10 walkman, but that's not to say that there aren't a lot of applications where the benefits would afar outweight the difficulty.
    • This article is about antenna arrays:

      Greetings from Tokyo and all the members of TIARA (Tokyo International Amateur Radio Association). I know I promised you a series of articles on Japanese amateur radio, but there is something so exciting I just have to take a break and tell you about it.

      It all started with the work that Ed Coan (AH7L/7J1AAE) did on antenna pattern plotting using his personal computer and the A-to-D converter in his FT-1000. The circular, and even backward antenna patterns of some of ou

  • I need to get one of those. (Score:3, Funny)

    by Rolo Tomasi ( 538414 ) on Tuesday May 04, 2004 @06:21PM (#9057347) Homepage Journal
    I just hope it won't interfere with my Vortex Field Generator or detune my Resonance Cascade.
  • Now I won't have to get an antenna rotator to get a good OTA HDTV signal!

  • If it works, why this application? (Score:3, Interesting)

    by Animats ( 122034 ) on Tuesday May 04, 2004 @06:23PM (#9057356) Homepage
    If this thing actually worked, they'd be selling it for applications that really need steerable directionality, like radars and satellite receivers. If they're selling it for "homeland security", it's probably not that good.

    The "war on terror" is turning into a pork program.

  • would you believe a flame speaker? (Score:3, Interesting)

    by ch-chuck ( 9622 ) on Tuesday May 04, 2004 @06:23PM (#9057359) Homepage
    Not rf from plasma, but audio [couger.com]

  • Hot Fresh Wifi while this light is lit!

    I wonder if the technology can be retrofitted to existing Neon signs. One of the main drawbacks to wifi is its relatively limited range and the cost of a decent antenna(cantennas excluded as these really aren't viable from an enterprise or business standpoint....think permenant installation)

    If every neon sign could be used as an antenna...think of all the coverage we could have. Vegas could work with Intel(centrino) to become the first unwired city. Get all

  • Hmm... so if the plasma antenna has variable beam width I wonder what that does for the gain of the antenna--It could replace very large traditional parabolic dishes on the transmit end. This could be great for mobile SNG satellite uplink, and also in space communications, that of course depends on the power requirements.
  • My first impression when they mentioned the directional plasma was something kind of like this. [postershop.co.uk]

    Yeah, so it was a long day at work..

  • Is that all? (Score:4, Funny)

    by AaronStJ ( 182845 ) <AaronStJ AT gmail DOT com> on Tuesday May 04, 2004 @06:30PM (#9057415) Homepage
    Highly directive and electronically steerable digital data transmission via solid-state semi conductor based plasma generators? Is that all? Heck, I've got, like, four or five solid-state semi conductor based plasma generators providing highly directive and electronically steerable digital data transmission in my car. Highly directive and electronically steerable digital data transmission via solid-state semi conductor based plasma generators aren't that big of a deal.

  • solution in search of a problem (Score:5, Interesting)

    by hak1du ( 761835 ) on Tuesday May 04, 2004 @06:39PM (#9057488) Journal
    We know how to make WiFi secure: with secure protocols and encryption. When the responsible standards bodies don't screw up badly (as they did with 802.11), it works fine. A somewhat directional antenna may or may not increase security slightly, but not at an interesting cost/performance ratio. If you really want additional security at the physical level, use laser or even quantum communications.

    This company has a solution in search of a problem, and they are trying to drum up businesses. Plasma antennas are interesting for 1960's style radio transmissions and stealth, but they have little significance to 21st century wireless communications.
  • I like to think of myself as a jaded techie, as are most of us here at /., I assume. But sometimes these little leaps in technology turn into BIG leaps, and it makes me wonder just how far forward we're going to go in my lifetime.

    And the good news is that so many of these technologies have as many uses for good as they do for evil!

  • You can circumvent the use of a Gas Plasma Antenna, and cost by using a simple Parabolic Antenna. It is just as effective with direction reception and broadcasting, which is all a Gas Plasma antenna can do. And being able to alter reception directions quickly does very little for security, possibly a bit of convienience, but I would like to save my money for other things.
    • Imagine if your car radio could stay locked on a signal with a directional antenna as you drive around, even exploiting reflections and multipath for optimum reception.

      All with no moving parts, and sub-millisecond times to "rotate" the antenna..

      Like one of those advanced phased arrays that the military uses, but in something the size of a hand held radio.
  • An SOS message could be sent by igniting three short farts, followed by three long ones, followed by three short ones.

  • Oil of Snake (Score:4, Insightful)

    by sillivalley ( 411349 ) <sillivalley@PASC ... t minus language> on Tuesday May 04, 2004 @06:59PM (#9057671)
    While the plasma may disappear when the antenna isn't in use, the housing containing the plasma doesn't. Not too stealthy...

    Another minor issue -- what's a plasma? Ionized gas, right? How do you ionize gas? By passing current through it. That gives you a large plasma arc. Gee, I wonder if just possibly that arc might be generating RF on its own? Any guesses on DC to light (literally -- gas discharge lamps give off quite characteristic spectra)? That arc is a very wideband RF source.

    You're telling me you're going to hook up a sensitive receiver to a gas arc, and it's going to work? Or you're going to hook up a transmitter to a gas arc, and the extra power from the transmitter isn't going to alter the characteristics of the plasma?

    Kind of like playing the violin while sitting atop a foghorn...

  • Speakers (Score:3, Interesting)

    by leighklotz ( 192300 ) on Tuesday May 04, 2004 @07:06PM (#9057753) Homepage
    I remember reading about making a speaker out of a candle or gas jet, I think in an old ham radio magazine from the 1950's. From what I remember, you stick two wires into the flame and drive it with a high voltage modulated with audio.
    • Yeap Plasma Speakers: They put a lot of R&D into them in the 1970's--The required a lot of power to work (like 800 watts for the tweeter) and had nasty RF. The biggest problem was that these ion speakers turned all the air into room into Ozone. This ment that the ones that where made required that it be hooked up to a helium tank.

  • Something Similar Exists... (Score:3, Interesting)

    by Mister Transistor ( 259842 ) on Tuesday May 04, 2004 @07:17PM (#9057944) Journal
    Actually they have already done this with a speaker. A gas makes a pretty blue flame, and by inserting electrodes into the base of the flame, and modulating it with a voltage, it causes the shape of the flame to change. This emits sound as it moves the air around the plasma jet.

    Several designs for these have been written up and have even produced comercially in Europe. U.S. Safety laws have prevented them from being sold in Amercia, however some enterprising scientists have built their own for fun.

    If the surface or volume of the plasma ball can conduct, it can be used as a radiator of RF, one that can have its shape dynamically changed by the above technique.

  • Errr ... (Score:2, Funny)

    by fullofangst ( 724732 )
    Gas Plasma antennas? The phrase "Gas Plasma" makes me think of a star trek episode where the enterprise accidentally destroys an ecosystem after venting warp plasma into a planets atmosphere :)

    Anyway, this would be a cool technology. Someone spying on your WiFi network? Send some gas plasma in his direction and watch the fireworks :D

    • The phrase "Gas Plasma" makes me think of a star trek episode ... accidentally destroys an ecosystem after venting warp plasma

      It wouldn't matter, they would have changed the laws of physics back again in time for the next episode.

      Plasma isn't technically a gas, it's a different phase, but sort of acts like a wet gas - you see it in flouresant lights and hot plasma is often used to cut steel in industry (plasma cutter).

      Someone spying on your WiFi network? Send some gas plasma in his direction and watch th

  • Backscattering (Score:1, Informative)

    by Anonymous Coward
    This sounds like mostly B.S.

    At microwave frequencies (at which Wi-Fi operates), just about every object scatters (reflects, diffracts) incident radiation. As a matter of fact, many RF antenna designs are "parasitically" directional, but rely on backscattering to produce a more omnidirectional response.

    Assuming that an adapative antenna array (which seems to be what the original press release describes) can target a specific client, sensitive near neighbors will inevitably be able to eavesdrop. Furthermo
  • Methinks I need to start heatproofing my Pringles cans.
  • One of the main advantages here seems to be that the antennas aren't metal. That makes them physically lighter and reduces noise by bunches, and doesn't reflect incoming radar when it's turned off. This is definatelly a military app.; especially in that is can be used as a radar antenna. Sounds perfect for airborne early warning radar systems.
  • Its complete rubbish to consider that plasma antennas could be used for WiFi. All of the plasma antennas I've heard of need something to contain the gas in which the plasma is excited. So your normal antenna is replaced with a glass vessel of a size larger than the largest antenna you want to have.

    Directivity comes at the cost of size. Sure you want 30dBi gain for your WiFi, I'll build it for you, but it'll be at least 10 wavelengths in size (1.25 metres for 2.4GHz WiFi). The only applications I see permi

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