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The Incredible Shrinking Antenna
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."
Does this even work with a hand holding the plastic case?
~~~LXT~~~
Life is like a computer program: anything that can't happen, will.
Great, now my phone is gonna be so tiny I can put it on my keychain!
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.
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.
Good quote, too many chars. Seriously, the slashdot 120 char limit sucks!
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?
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).
Or you can just plug yourself into a high-yield electrical outlet and become the antenna!
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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.
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.
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And the people shall be oppressed, every one by another, and every one by his neighbour Isaiah 3:5
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?
Imagine all the implanted execs actually looking forward to boring meetings to call up their dial-a-pr0n.
With antenna-less phones, like the Nokia 8260 and the Nokia 3360, I don't worry about antennas anyway, and these phones are here now, and work with my wireless company!
Disclaimer: I'm not an employee of either, but I do use rogers...
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Some weasel took the cork out of my lunch.
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
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.
Bush's education improvements were
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.
Amusingly, Slashdot rejected an article submission I had for fractal antennas 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.
Bowie J. Poag
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.
Lemon curry?
Anybody know the physics (or lack thereof) behind these things?
since noone has posted it yet, i guess my karma-whoring is as good as any ..
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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..
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Just think if this had been available during the CIA's
Operation Acoustic Kitty 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.
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This may be the first time that a General Manager has accomplished anything!
Conformity is the jailer of freedom and enemy of growth. -JFK
I thought that your antenna size was related to the size of your feet?
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.
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.
This next song is very sad. Please clap along. -- Robin Zander
Matching foil underwear might be nice, too. For the man who has everything....
"Those who have never entered upon scientific pursuits know not a tithe of the poetry by which they are surrounded."
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. I don't remember which SciAm article I read the story from but I think it was in 1999.
I'm a loner Dottie, a Rebel.
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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