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Technology

The Incredible Shrinking Antenna 184

Posted by CmdrTaco from the two-inches-is-plenty dept.
pinkUZI writes "NYTimes ran an article yesterday about a new material, created by a general manager at Integral Technologies, that would enable use of the plastic mold of a cell phone as its Antenna. Pretty neat, as it actually increases the size of the antenna while decreasing the footprint."
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The Incredible Shrinking Antenna More

The Incredible Shrinking Antenna

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  • Capacitance? (Score:3, Interesting)

    by LoonXTall ( 169249 ) <loonxtall@hotmail.com> on Friday March 08, 2002 @10:34AM (#3130268) Homepage
    Does this even work with a hand holding the plastic case?
    • I don't see why it wouldn't. Your antenna on your car isn't affected a large amount if you grab it. And, who knows, if you have a metal plate in your head, it may increase your signal by several orders of magnitude. I can see it now, no roaming, even from China
    • Sure. Imagine holding a phone with an internal metal antenna -- it's almost the same thing, just a few extra millimeters of distance.

  • Shrinkage = Bad (Score:2, Funny)

    by Duckz ( 147715 )
    Great, now my phone is gonna be so tiny I can put it on my keychain!

    • Re:Shrinkage = Bad (Score:4, Funny)

      by Brento ( 26177 ) <brento AT brentozar DOT com> on Friday March 08, 2002 @10:37AM (#3130291) Homepage
      Great, now my phone is gonna be so tiny I can put it on my keychain!

      What's so bad about that? And come to think of it, a keychain might make a decent antenna if you could wrap the wire right...

      • Re:Shrinkage = Bad (Score:2, Insightful)

        by Duckz ( 147715 )
        The Nokia 3360's and smaller phones are very annoying. I want a phone large enough that I dont feel like I need to be moving the phone up to my ear when listening and down to the mouth when talking.

        I know they work well, but I feel like I have to do that, and the smaller they get the worst that 'feeling' will be.

        --
        Todd

        • Re:Shrinkage = Bad (Score:2, Interesting)

          by jeffy210 ( 214759 )
          Actually, I have an 8260 (even smaller than the 3360) and it works just fine holding it normally. The mic is good enough to pick up your voice at a normal volume when it is next to your ear. You don't have to consistently move it back and forth for the other person to hear you. Coupled with the headset and sometimes it feels like the person is right next to me. Maybe it is the area that you are in?

          • Re:Shrinkage = Bad (Score:3, Informative)

            by Galvatron ( 115029 )
            He didn't say it doesn't work, he said it doesn't feel right, and I agree. I want what I'm talking into to be in front of my mouth, not over on the side of my face. Besides which, it seems that these small phones unconciously causes people to talk louder, to the point where many people on cell phones are almost shouting, to the great annoyance of all around them.
            • Kind of like the people who think that they can/can't hear with glassess on/off? Tell me, when you talk to someone in person, do you put their ear in your mouth? :)

              Seriously, it's understandable why the asthetics of a phone (or any such device) would lead to use that was not intended by the designer. As long as there is a demand for phones that have mics close to the mouth, someone will make 'em.
              • Actually, I am one who suffers from the glasses deal...if my glasses aren't on, I can't hear. Sounds strange, but really makes since. My hearing isn't that great either. I found out I am subconciously (sp?) reading lips. One of my coworkers has the same condition.
              • No, but I do face them when I talk. My mouth is still pointing in the direction that I am projecting sound. Do you stand at right angles to people when you talk to them?
    • Hehe, when I read the heading, I immediately thought of a cold swimming pool on a hot summer day with your bikini clad girlfriend watching you get out after a quick dunk. OWIE! Seriously, I have to agree about phones being too small. My wife and I just switched off our land line in our apartment and went with two cell phones as it is cheaper. We got a good deal from verizon on service and two motorola mid-range 3system phones. These are largish phones compared to flip phones, and I still find them annoyingly small. I don't mind thin, but they are too short. You can't cradle them well on your ear or anything! And I get this feeling like I should be moving it from my ear to my mouth and back in a conversation (though you certainly don't have to), and manipulating the three little speaker hole grill over your ear so you can hear correctly takes some getting used to as well.
  • With Intel planning on integrated circuits with radio antennas built in by 2010, I wonder if this technology can me melded to provided better range and gain. For example, if your PDA is the size of a 100mm square chip and is embedded in your neck, you can get a range of 10 meters instead of one.

  • Brain Cancer? (Score:3, Interesting)

    by FortKnox ( 169099 ) on Friday March 08, 2002 @10:36AM (#3130284) Homepage Journal
    How does this affect the old "Brain Cancer" study for cell phones?

    I heard that you want the antenna pointing out, not up, now the whole phone's the antenna.

    Anyone know the dealio with this? IANAD, so please take this with a grain of salt.
    • Moreover- from the article:

      When the antenna is structurally embedded in a car, it becomes "a very effective radiator" of electromagnetic waves, said Alan L. Haase, chief executive of Skycross. An antenna built into the walls of a building could do the same thing, he said.

      That's what we need, millions of E&M sources built into the plastic surfaces around us...

      On the bright side, the article says the material is such an effective conductor that antennas can be smaller with lower power usage. Hrm, but that doesn't mean the E&M fields are smaller.
      • It implies it. EM field size is partialy controlled by power. If the frequency stayed the same, then you would have less power, over a larger area (dissapated). That's good, but I'm still nervous about having a transmitter that close to my head.
    • All thorough studies with this topic have demonstrated no statistical significant difference between the general population and those that use cell phones.
    • I'm not worried about brain cancer. I'm worried about growing even MORE hair on my hands. I've got enough as it is.

  • 1) Place said cell phone into a cold swimming pool.

    2) Watch and learn.
  • I'm definitely not the athority on this subject, but i thought the antenna was tuned to the proper frequency and that making it longer (or shorter) would make it less effective. Anybody want to speak to this?

    • Re:Longer = BAD, right? (Score:5, Informative)

      by Beryllium Sphere(tm) ( 193358 ) on Friday March 08, 2002 @11:15AM (#3130469) Journal
      Good question!

      A resonant antenna, cut to exactly half a wavelength, has some advantages but it's not a necessity.

      The advantages are simpler circuit design, because it looks like a pure resistance and doesn't confuse the amplifier, and in theory a simple radiation pattern.

      In practice the pattern will depend on everything in the environment, so good antenna testing is Very Difficult. Take all claims with a grain of salt until you hear that the antenna has been tested on an expensive antenna test range by experienced people.

      When you're dealing with small fractions of a wavelength longer is better. For very short antennas, only a small fraction of the RF leaves as radiation before it's lost as heat from electrical resistance. "Longer is better" means "longer is more efficient".

      BTW you can take advantage of how antennas are affected by nearby objects. If you're in a fringe area, try standing right next to your car, with the base of the antenna level with the roof line. Circle around the car until you're in the right alignment with the cell tower for further optimization.

      Fred KC7YRN

    • Re:Longer = BAD, right? (Score:2, Informative)

      by vyzar ( 11481 )
      Longer does not necessarily mean bad, or good.

      Antennae do have to have certain characteristics to resonate and therefore radio a signal effectively, but like many things in life, there is more than one way to do this. It all comes down to the length of the antenna relative to the wavelength of the signal.

      There are various "good" ratios of antenna length to wavelength. And the larger the antenna the better provided that the fit the "good ratio" models.

    • Re:Longer = BAD, right? (Score:4, Informative)

      by SWPadnos ( 191329 ) on Friday March 08, 2002 @11:19AM (#3130491)
      Nope.

      The frequency of an antenna is determined by its' size and the speed of current flow in the material (among other things). The "tuning" of an antenna is dependent on what fraction of a wavelength (at the frequency of interest) is present on the antenna element(s) at one time. This is where you get the terms quarter-wave, half-wave, etc.

      A measure of the effectiveness of an antenna is the "capture area". This is the effective size of the antenna. The conductivity of the material is important here - the better the conductor, the smaller the antenna can be made. (actually, some research shows that a superconducting antenna could be infinitessimally small, and still give the capture area of a full-wave antenna.)

      There are a zillion variables in antenna design, and it seems like voodoo, but the net effect is that you can change a bunch of parameters, including the size, and end up with many different antenna configurations tuned to the same frequency.
    • The length of antenna may be lambda by 4, or mebbe lambda / 8 (lambda is wave length of EM Wave for e.g. @ 950 MHz lambda ~= 32 cm, lambda/4 = 8 cm).
    • Antennas work best in multiples of the wavelength of the frequency. It is my understanding that antennas get better the longer they are, but that would only be true at multiples of the wavelength. I.E. if you antenna is tuned at a certain length, doubling it would be good, but just extending it a bit would cause the signal to get worse. Then again... I could be wrong. My dad's a HAM, but that doesn't mean I know anything. :)
  • This assumes that cellphones can give you braincancer (they certainly can give you headaches;)

    This makes the antenna bigger. That means that the phone will send the braincancer waves to a bigger part of your brain, don't it? And it will be more difficult to shield the antenna because the outside of the phone will be a complete antenna. Also a larger antenna doesn't neccesarely mean that it's better, I believe that for every wavelength there's an optimal size (if I remember correctly).
    • If that's the case it should only be better.

      A larger affected volume in the brain would actually lower the risks, think of a magnifier and an ant.

      Second, a more effective antenna could help in decreasing the effect needed to keep the link to the basestation and further reduce the risk.

      But there's always the point that the "shell antenna" will be selected for cosmetic reasons, only proper testing will tell you which phone to select if you are concerned about radiation.
    • This assumes that cellphones can give you braincancer

      Why assume that? AFAIK, the only argument ever advanced for this was from a guy whose wife died of brain cancer. She was constantly using a cellphone, and developed a tumor right next to where she always held the phone. The guys argument was essentially, "It's obvious! It *has* to be the phone that gave her cancer! What else could it be?"

      In actual studies there has been no correlation shown between cellphone use and brain cancer. A lot of people use cellphones, and have been for years. Wouldn't there be vastly more cases of brain cancer than there are, if it was such a risk?

    • Re:dangerous? (Score:2, Informative)

      by Maddog Batty ( 112434 )
      This assumes that cellphones can give you braincancer of which there is NO peer reviewed evidance.

      (they certainly can give you headaches;) not from the phone though speaking to the inlaws can cause this :-) There is some evidance that mobile phone use can improve your memory but that's about it. Mobile phones have not been proved to be safe but then this will never be possible. It has been proved that the dangers are far less than the dangers of using a mobile phone whilst driving which kills many many people every day.

      This makes the antenna bigger. That means that the phone will send the braincancer waves to a bigger part of your brain, don't it? The size of the antenna does change its performance but a larger antenna can mean either a performance gain or a performance loss. A simple antenna wants to be 1/4 of the wavelength of the signal it is transmitting. Either bigger or smaller will reduce its performance. You are also missing a very important point. An improvement in the antenna means that the signal driving it can be reduced so as to save battery life. The signal strength generated by a mobile phone is adjusted to be as weak as possible so as to just make a reliable connection. Therefore the radiated output from the phone will be the same.

      And it will be more difficult to shield the antenna because the outside of the phone will be a complete antenna. Mobile phone shields do not work. The phone simply increases the signal strength to compensate for any changes any so called shields provide. Transmission measurements in lab conditions have shown that shields make no difference at all.

      Also a larger antenna doesn't neccesarely mean that it's better. Correct. However a larger antenna "could" be better.

      I believe that for every wavelength there's an optimal size (if I remember correctly). The ideal length for a 1/4 wavelength antenna used on a mobile operating at 900MHz is 75mm. However, there are other options apart from 1/4 wavelength antennas.

  • Or... (Score:2, Funny)

    by NiftyNews ( 537829 )
    Or you can just plug yourself into a high-yield electrical outlet and become the antenna!

  • "a very effective radiator" (Score:5, Interesting)

    by mosch ( 204 ) on Friday March 08, 2002 @10:40AM (#3130304) Homepage
    Am I the only person who doesn't particularly like the idea of "a very effective radiator" next to my head part of the time, and next to my balls the rest of the time?

    It'd be nice to not have an antenna to break off, but I don't want it to be any more effective than the current ones, unless it's more directional, which the article does not indicate it is. More effective cell coverage seems a better solution to me.

    On the other hand, some of the other applications sound mighty nice, especially for military vehicles and such.

    • Am I the only person who doesn't particularly like the idea of "a very effective radiator" next to my head part of the time, and next to my balls the rest of the time?

      Then you had better stay away from table lamps - they're far more effective at spewing radiation than your cellphone

      • I think the quote from the article was: "When the antenna is structurally embedded in a car, it becomes "a very effective radiator" of electromagnetic waves...". So, unless you are storing a car in your pants, or attaching it to your head, you probably are ok. Actually, if you are storing a car in your pants, or attaching it to your head, you are a lot worse off.

      • What about laptops? PDA's? meters of utp cable?
      • Then you had better stay away from table lamps - they're far more effective at spewing radiation than your cellphone

        The last time I held a table lamp to my head Iwas told to see a doctor.. as for the time I held one to my balls.. well..

    • Actually, by the time this material is in widespread use, I expect to be using a bluetooth headset most of the time. Such a headset might isolate the antenna from your head a little better...just as when you extend the antenna on your mobile phone today. Since the distance to the handset is relatively short, the headset won't need a super-duper antenna. But it would be nice for the handset itself to have one of these to improve it's reception.
    • You really don't want a cellphone antenna to be directional - if it was, you'd have to point the cell phone directly at the cell site.
    • First off, it radiates radio waves, as you seem to understand. It doesn't radiate alpha particles or gamma rays or any such fission by-products. It's radiation, but not nearly as bad as the name implies to some.

      Some persons believe the EM radiation given off by cell phones is a hazard to your health; I actually tend to agree. The problem is, you can't make it less of an issue by using a crappy antenna. If the antenna is worse, you just generate a stronger signal to overcome that limitation. The power needed to contact the cell tower remains the same.

      So, you will have the same amount of radiation emitted into your brain cave whether or not the phone's antenna is efficient. You might as well just get an efficient antenna and save batter power, instead of holding back the tech out of paranoia.
      • There was a widely reported study (in the US anyway) about radiations of various cellphone and their possible connection to brain cancer. This report was also broadcasted on 60 minutes or 20/20 or Dateline (one of those news magazine, forgot which).

        And essentially, it came out that the Motorolla Startacs were the best because the the flip design - the antenna is at an angle, farthest from your head, and partially shielded by the part of the cellphone that flipped up (I don't think Motorolla designed this phone thinking about brain cancer, they just got lucky). The worse were the Nokias where the antenna is straight up on top of the phone and so when you talk on the phone is close (if not touching your head).

        I guess what I am getting at is that the original poster definetely has a point. If you make the whole casing of the cell phone the antenna, wouldn't that potentially be bad? It's one think to have radio wave all over the air, it's another to stick your head on the emitter.
        • ...and eye cancer [com.com] [com.com] [com.com] (just to emphasize the rather ridiculous domain name:P). Although this study was a bit small (as the researchers say themselves), the results aren't too accurate. But the conclusion is that cellphone users are 3 times more likely to develop cancer of the eye.
    • "applications sound mighty nice"

      Combine this technology with a flat panel speaker in your LCD screen, and some batteries created using similar technologies where the case (dammit the KEYS) of your laptop ARE the battery and you get one hell of a light, dense piece of kit.

      With an antenna of that area you'd get great reception even in MY house!
    • All you need is a long fishing rod attached to your hat (you do wear a hat, don't you?) with the cell phone dangling from it, a good six to nine feet away.

      That's what I plan to do when I get a leash... Urrr...cell phone.
    • So better check that out before u try reheating that mug of milk.
    • Matching foil underwear might be nice, too. For the man who has everything....

  • Ummm what external antenna? (Score:4, Insightful)

    by CProgrammer98 ( 240351 ) on Friday March 08, 2002 @10:41AM (#3130308) Homepage
    My Nokia 3330 (and I believe most nokias) already doesn't have an external antenna, so what's the big deal? Perhaps the antenna would effectivly be larger but again, I don't see a great deal of point in that, it's very rare that I get less than about 75% signal strength already, and there's more cells going up all the time.

    .
    • I have the 3390, and it's the same thing. I'm in a poor reception area as it is, but my signal strength is usually pretty good. Now my service provider on the other hand...
    • Yes, but look at it from the perspective of the cell phone signal providers. They can sell more phones if 1) their phones can pick up signals from further away and 2) they save money because they don't need to have as many towers for coverage.


      While I'm not an electrical expert, I see tons of potential for this. How about instead of that ugly TV antenna on your house, you just place a conductive plastic layer all over your roof?

      • interesting points - but here in the uk, there is already an awful lot of overlap between cells and we're almost at 100 % coverage - I guess they could tear down some cells to save on running costs.

        We have cable tv so the roof analagy doesn't apply to me but I take your point :)

        • Additional (seemingly redundant) towers are erected to provide additional capacity, not necessarily to improve signal strength. More towers operating at lower power (and instructing the phones to transmit at lower power) means more people can use the same radio frequency.
    • on these phones the antenna is internal.
      If you open the back case the plate at the top below the power button and behind the screen is the actual antenna, just think how much smaller the phone would be if this could be removed. the biggest part of a phone would become the battery.
      • My phone is already tiny enough - but maybe there's mileage in reducing the size of integrated pda/phone type devices - but even with those the limit is the screen size, you can't make that too small.


        Possibly when we get truly wearable computers where the image is projected directly onto your retina (which would be really cool for me as I'm already a spectacle wearer) and the cpu etc is a little box in your pocket, then I can understand how it would be beneficial.

    • I design cellphone ICs for a living, so I can tell you that this could potentially be a "big deal". Reason is that high gain antennas mean you can either get longer range OR you can get the same range at a lower power.

      If the PA (power amp) in the phone was connected to a high gain antenna, and did not have to put out as much power to reach the cell tower, that translates directly into a major power savings (the PA is one of the dominant power drains). Power savings means I don't need as big of a battery in the phone, which means I can shrink the battery and make the phone lighter and smaller and (very importantly) cheaper. Phones that are lighter and smaller sell better, this means $$$ for anyone who can make it work.

      And of course when the company makes $$$, that means big bonuses for all us working in the trenches, which gets back to the "big deal" part..

      • Thanks for the excellent explanation, now increased battery life and smaller power output I would defineitly go for! As to phone size, they're already way too small for a lot of people (including my wife) - my llast phone was the Motorola v3688 which was tiny (but crap battery life) and now they're making them even smaller - unless you want to walk around with a headset/mic all day long, most curreny phones are too small.

        .
    • The big deal is, it would use LESS BATTERY POWER.

      I cannot believe you don't get less than 75% signal. Have you never been inside a building and have it disappear in the lifts? While some places you will still have non 0% in the lifts.
  • You don't want the output power to actually be doubled...you want it to be just right, and your output power is effectively government by the cellsite that you're using for your upstream transmission.

    So hopefully this will just end up as a more *efficient* antenna and not a more powerful one ;-)

    I can also see some cellphone manufacturers not wanting to cast their phones in silcone -- preferring ABS.

    Plus, I wonder that without an RF "hotspot" where the antenna is, would this phone have a *better* chance of irradiating your head?

    • Plus, I wonder that without an RF "hotspot" where the antenna is, would this phone have a *better* chance of irradiating your head?

      I'd been chuckling at the em-irradiating of the head comments until I read this one. It actually presents an interesting thought...

      A standard antenna radiates from where the antenna is, thus bombarding the area of the head closest to it with strong EM waves. But, with the whole phone broadcasting the waves, the antenna is larger, power output observed near infinity is the same (because, as you say, the output power is 'just enough'), and therefore the average power/cm^2 of antenna is lower. Therefore, you have a larger area of the head being bombarded, but with a significantly reduced power level. I'd tend to say that the lower power level received per cell (biological cell, not cell-tower cell) would actually make the larger/less powerful antenna better for you.

  • CyberPhone? (Score:2, Interesting)

    by Aaron_Pike ( 528044 )
    You know, some rejection-resistant artificial bones are made of plastics. Cochlear implanted speakers, remote control (or heck, subdermal) input for dialing and playing wacky snake games, subvocal microphones, and you've got an extremely subtle telephone system.

    Imagine all the implanted execs actually looking forward to boring meetings to call up their dial-a-pr0n.

  • Shocking! (Score:1, Funny)

    by FurryFeet ( 562847 )
    Gotta love those dry days, when you're walking on a thick carpet and your phone rings.
    Hope you don't keep it in your pants pocket.

  • Redundant? (Score:2, Informative)

    by DickPhallus ( 472621 )
    With antenna-less phones, like the Nokia 8260 [nokia.ca] and the Nokia 3360 [nokia.ca], I don't worry about antennas anyway, and these phones are here now, and work with my wireless company [rogers.ca]!

    Disclaimer: I'm not an employee of either, but I do use rogers...

    • Re:Redundant? (Score:3, Informative)

      by monkeydo ( 173558 )
      Uh, the antenna on those phones is inside the case. This technolgy would allow the case to be the antenna, eliminating the need for any seperate internal or external antenna. This in turn allows the phone to be smaller and more efficient.
      • But take a look at the dimensions on those phones? Do they really need to get any smaller? Besides, battery size and the size of the human finger will keep phones around the same size they are now, because if they actually get any smaller, they will be harder to use.

        • Re:Redundant? (Score:3, Interesting)

          by monkeydo ( 173558 )
          Fuel cell technology will enable smaller batteries, and in the future your phone may be nothing more than a card in your wallet and you will talk on your wireless headset.

  • Will a longer antenna be helpful or harmful? (Score:5, Informative)

    by Muddie ( 72996 ) <larry.runswithscissors@com> on Friday March 08, 2002 @10:48AM (#3130339) Homepage
    800 MHz cellular has a wavelength of approximately 37 centimeters, about 15 inches. So an ideal antenna would be half that, about seven and a half inches. This refers to the dipole, the distance from the tip of the antenna to the opposite end of the antenna buried inside the phone somewhere (usually near the bottom). 1900 MHz PCS has a wavelength of approximately 16 centimeters, about six inches. So the ideal antenna dipole is about 3 inches.

    The ideal antenna performs best if it is exactly perpendicular to the impinging waveform. In practice the orientation of the phone is somewhat random; the antenna will be pointed approximately upward, but probably at a slant. So cell phone manufacturers generally try to make the antenna 5/8's of a waveform, because if the antenna is at a slant, its cross-section relative to the impinging waveform will be near to the ideal half a wavelength. For a dual-band phone, one which operates at both 1900 and at 800 MHz, it's obvious that determining the antenna length is a bit of a problem. (But not insoluble; it's just a compromise. Since digital is usually more resilient than AMPS, usually the length is optimized for 800 MHz.)

    Making the antenna shorter will both decrease the amount of incoming signal the phone receives, and will make the phone's transmitter less efficient. But CDMA operates over a very wide range of effective powers, and it can usually compensate. That's why the phone will usually work with the antenna down. And because it's digital, if it is working it will sound exactly the same. This has lead some people to conclude that the antenna is not actually doing anything for them, which is not quite correct. While the phone can operate with the antenna down, it's easier on the phone if you raise the antenna; it has more signal ceiling to work with and will be less likely to drop the call. Also, it will use somewhat less transmit power, and your battery will last somewhat longer.

    Making it longer with some sort of extension is worse than useless; it actually degrades the signal. If the antenna is exactly one wavelength long and is exactly perpendicular to the impinging waveform, it will pick up essentially no signal at all.

    When it reaches one and a half wavelengths, signal strength is again maximized, but for physical reasons it's a bit lower than the strength with a half-wavelength antenna. (The physical reason is that the antenna is not an ideal conductor.)

    [stolen directly from the CDMA FAQ [denbeste.nu]
    • The ideal antenna performs best if it is exactly perpendicular to the impinging waveform.

      This is somewhat misleading.

      You should really be talking about the relative orientations of the TX and RX antennas.

      It then depends on the polarization of the RX antenna and the polarization of the TX antenna.

      If the incoming wave and the antenna have the same polarizations, and the antenna is "perpendicular" to the incoming wave, you'll actually get 0 signal. You want the antenna to be "parallel".

      What cell phones really need from improved performance is diversity, i.e. 2 antennas, perferably of differing polarizations.

      • What cell phones really need from improved performance is diversity, i.e. 2 antennas, perferably of differing polarizations.

        That would involve something like a turnstile antenna [cebik.com].

        Those four elements you see in the top picture would each be 3.5" long. You could call them "ugly sticks", because there's no way you could conceal more than two of them in a cell phone's case.

        If the incoming wave and the antenna have the same polarizations, and the antenna is "perpendicular" to the incoming wave, you'll actually get 0 signal. You want the antenna to be "parallel".

        In theory, yes, in empty space one can get over 30db of signal discrimination by choosing the opposite polarization - in practice however, the signal bounces all over everything between your cellphone and the tower, so signals of all polarization get through. Otherwise you'd instantly drop calls every time you held your phone horizontally or pointed your phone's dipole directly at the tower (assuming your phone could only reach one tower).

        Cellphone towers are all vertically polarized (almost all amateur and business-band radio is as well). Broadcast TV/radio is horizontally polarized.


  • From the article:

    "Integral is even talking to a provider of satellite tracking services about turning truck bumpers into giant antennas by making them out of a rubbery blend of the new material."

    Although it has improved in recent years, the quality of reporting of technical issues is often very poor. Truck bumpers are already metal. Why not just insulate them from the truck body, and use that as an antenna? The article does not say.
  • Here we are talking about cell phones and some of the paranoid folks are worrying about brain cancer (although there is no statistical significant difference between cell phone users and non users) and I see the quote at the bottom of the page. Arnold's Addendum: Anything not fitting into these categories causes cancer in rats. made me laugh...
  • Can one make replacement battery covers or back covers that would serve as the antenna? My tiny little Nokia with the internal antenna could sure use some help.

  • This is nothing..try fractal antennas. (Score:3, Interesting)

    by Bowie J. Poag ( 16898 ) on Friday March 08, 2002 @10:50AM (#3130354) Homepage


    Amusingly, Slashdot rejected an article submission I had for fractal antennas [fractenna.com] and how they are vastly superior in terms of reception to whats on the market today. Better than the stuff mentioned in this article, certianly.

    Cheers, and yes PROPAGANDA will be back soon.

  • I wonder what (Score:2, Interesting)

    by MsWillow ( 17812 )
    What the changes in impedance will be from user to user? Will having sweaty palms make much difference? And, while a larger antenna might seem better, would it be directional, varying with the shape of the phone?

    I'm not sure that I want my hand and face even closer to the source of the RF radiation. Doesn't the field strength vary with the inverse cube of distance? There's not much distance when you're touching the antenna.
  • So, your telling me that a general manager created this? Riiiight. Most general managers can't even turn on a cell phone without being shown 2-3 times first. I bet some poor shlub from engineering created it first and the manager took all the credit. ;)

    • Re:Uhuh... (Score:3, Insightful)

      by pclminion ( 145572 )
      So, your telling me that a general manager created this? Riiiight.

      My manager designed antenna assemblies for the space shuttle. He also designed parts of the Mariner system for the Venus landings. He wrote code for computer systems that are designed to reboot themselves every 30 milliseconds. You try coding under that kind of constraint.

      The president of the company did spooky work on spy satellites. He still won't talk about it. But man, that guy hates Communists with a passion...

      And both of them could code circles around 99% of the people on Slashdot. Just because a person becomes a manager doesn't mean he becomes an idiot.

      • Please not the ;) as I was JOKING. Sheesh.

      • Re:Uhuh... (Score:3, Interesting)

        by david duncan scott ( 206421 )
        I believe you, BUT did they do those things while they were managers, or before they were promoted?

        It's a real problem, one that both IBM and many school systems face: how do you reward your best people? Traditionally, they get promoted, and one often finds that great researchers then become competent administrators (if you're lucky). You've lost a PhD and gained an MBA. Similarly many teachers become principals and are lost to the classroom.

        IBM came up with Fellowships for these guys -- recognition and money, but they can still get their hands dirty. Some school systems are creating titles like "Master Teacher", and giving them some authority to buck the system but letting them continue to teach.

  • How easily can this be ported to say using a plastic computer case for an antenna for wireless lan or how about a cordless phone? With all the plastic in cars ... imagine the reception you could get? Would this mean that my alarm radio will finally get good reception? Could I finally have a decent wireless link for my TiVo!?
  • What about those little "tape-in" antennas they're advertising on TV all the time these days? Do they do anything at all? What I see in the ads makes me highly doubt they change anything. It seems like some good old-fashioned snake oil to me --- something for the suckers.

    Anybody know the physics (or lack thereof) behind these things?

    • all fake (Score:3, Interesting)

      by rebelcool ( 247749 )
      ive lost the link to the article, but the FTC is taking them on for deceptive marketing. they do nothing, and in some cases, actually reduce reception..
      • That's what I thought. I couldn't think of ANY physical reason why those things should work.
        • Just out of curiousity, I bought one of these for a few bucks at a computer show last year. I had the field test codes for my phone (Samsung SCH-3500, Sprint PCS) and a wide open area outside the computer show to do my testing.

          It did improve reception a very small amount, but only in some cirsumstances. End result, I could walk up and down the stairs in my house without the call dropping, and I could stand about 2 feet further from the window than before (reception at that house was awful). I've since moved on to a better phone, and I don't lose calls except when the network drops out completely (one of the local towers here does that for a few seconds every couple of minutes; everyone with a Sprint phone loses the signal completely).

          So are they great? No. Will they let you talk in an elevator? Probably not. But I did have a few less dropped calls, and that was worth $6 or so.
    • What about those little "tape-in" antennas they're advertising on TV all the time these days? Do they do anything at all

      Yes. They separate the ignorant from their money. For more information see: Barnum, P.T.

      --Jim

  • login-free link (Score:2, Informative)

    by shivan ( 12148 )
    since noone has posted it yet, i guess my karma-whoring is as good as any ..

    login free link [nytimes.com]
  • Just think if this had been available during the CIA's
    Operation Acoustic Kitty [slashdot.org] program? They could have made kitty dentures be the antenna, instead of that "hard to maintiain" tail.

    Of course, it'd still have problems with wandering away & getting hit by traffic...
  • ...in my opinion, is that a general manager did something useful.

    It's a sure sign of the End Times. Gotta be. We'll be seeing pigs fly, next.

  • Score one for the pointy-haired bosses! (Score:3, Funny)

    by duffbeer703 ( 177751 ) on Friday March 08, 2002 @11:17AM (#3130482)
    This may be the first time that a General Manager has accomplished anything!
    • nope... only tricked people into thinking it's an accomplishment. Ask the HAM people why they don't use the roof of their house as an antenna :) Even if it did work, it would transmit harmonics more than the actual signal. That's wasted wattage. They just need better antennas and less wattage, not some crackpot that thinks bigger is better. (really only true for a dish)

      Sadly, I think the score is still 0. You'ld think you would have to know something to be a general manager :)
  • My cell phone is already on my 'coins' pocket, it is really small. The only think big is the antenna and the battery. If you could also put the battaery small enough and still with a lot of power, we could have a real tiny cell phone.
  • it actually increases the size of the antenna while decreasing the footprint

    I thought that your antenna size was related to the size of your feet?

  • Imagine just how much Cartman must wish the aliens had that kind of technology after recieving an anal probe from them.
  • I wonder what something like this could do for my 802.11 airport network.

  • Tumor as an antenna tuner (Score:1, Funny)

    by Anonymous Coward
    Like it or not, your head is part of the antenna. As the microwaves bounce around up there, the tumors would form in areas where the radiation was highest. Once the tumors got to sufficant size, they would resonate, giving you a better signal.

    So, if you all the sudden find that your cell phone is working really good, even in remote places....
  • I guess they wanna embed the antenna in between layers of plastic, similar to what is done on laptop casings for ground plane.(But what about the loading inductor???)
  • A couple years ago I read about a similar thread of research concerning fractal antennas. You can eiter have an array of fractal elements or a single wire bent into a fractal shape. With the array of elements you can get the range and reception qualities of a random antenna array and still have an efficient system like a regular array. With a single wire you it ends up needing only a fraction of the space it needed before for the same length wire. You can fit a half wavelength dipole inside the housing of the phone quite easily. Jagging the shape of the wire introduces natural capacitance and inductance so less external equipment is needed to tune the antenna. IIRC the single wire antennas used Koch curves. The people who started the research on them formed a company called Fractal Antenna Systems who are trying to work with eantenna manufacturers. Sych antennas could be molded into the plastic case of a cell phone AND be 20% more efficient. A link to Koch curves (java is a good thing to have) is here [colostate.edu]. I don't remember which SciAm article I read the story from but I think it was in 1999.
  • There are lots of conductive plastics, so this isn't exactly new. Furthermore, you can bend wires into any shape you want. It may or may not be a little more expensive to manufacture, but a company that wanted to have an antenna that doesn't stick out could bend a wire and route it around the case. Or, they can just print the antenna on a flexible printed circuit board (which some do). In fact, many cell phones have the antenna be an integral part of the case.

    In fact, there are several cell phones that use integral antennas. Why don't all have it? I suspect it's because an antenna that sticks out beyond the part of the phone that is covered by your hand probably works better.

  • This is completely foreign to my experience! A general manager creating something other than a spreadsheet or a headache?

    I'm inclined to believe a person was promoted to general manager for technical chops they earned in the past, or maybe even because of this wonderful invention. But was this person a general manager *when they created* this device? Not likely! I want to work at that company.
  • Isn't the whole point with external antenna to spread the EMF radiation away from your brain? If the plastic is part of the antenna, wouldn't it just bring it closer?

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