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Engineers Discover How To Make Antennas For Wireless Communication 100x Smaller Than Their Current Size (sciencemag.org)
Engineers have figured out how to make antennas for wireless communication 100 times smaller than their current size, an advance that could lead to tiny brain implants, micro-medical devices, or phones you can wear on your finger. Science Magazine reports: The new mini-antennas play off the difference between electromagnetic (EM) waves, such as light and radio waves, and acoustic waves, such as sound and inaudible vibrations. EM waves are fluctuations in an electromagnetic field, and they travel at light speed -- an astounding 300,000,000 meters per second. Acoustic waves are the jiggling of matter, and they travel at the much slower speed of sound -- in a solid, typically a few thousand meters per second. So, at any given frequency, an EM wave has a much longer wavelength than an acoustic wave. Antennas receive information by resonating with EM waves, which they convert into electrical voltage. For such resonance to occur, a traditional antenna's length must roughly match the wavelength of the EM wave it receives, meaning that the antenna must be relatively big. However, like a guitar string, an antenna can also resonate with acoustic waves. The new antennas take advantage of this fact. They will pick up EM waves of a given frequency if its size matches the wavelength of the much shorter acoustic waves of the same frequency. That means that that for any given signal frequency, the antennas can be much smaller. The trick is, of course, to quickly turn the incoming EM waves into acoustic waves.
The team created two kinds of acoustic antennas. One has a circular membrane, which works for frequencies in the gigahertz range, including those for WiFi. The other has a rectangular membrane, suitable for megahertz frequencies used for TV and radio. Each is less than a millimeter across, and both can be manufactured together on a single chip. When researchers tested one of the antennas in a specially insulated room, they found that compared to a conventional ring antenna of the same size, it sent and received 2.5 gigahertz signals about 100,000 times more efficiently, they report in Nature Communications.
The team created two kinds of acoustic antennas. One has a circular membrane, which works for frequencies in the gigahertz range, including those for WiFi. The other has a rectangular membrane, suitable for megahertz frequencies used for TV and radio. Each is less than a millimeter across, and both can be manufactured together on a single chip. When researchers tested one of the antennas in a specially insulated room, they found that compared to a conventional ring antenna of the same size, it sent and received 2.5 gigahertz signals about 100,000 times more efficiently, they report in Nature Communications.
Lemme guess... we just proved the science and now just need to work out the small technicalities. Brain implants in 3-5 years.
Fast Federal Court and I.T.C. updates
What about antennas for Over-The-Air television? I know transmission frequency is way lower than cellular communication signals, but could there be better signal-to-noise ratio for TV? With all the cord cutters out there...
Does it break the Chu Harrington limit? How is the noise performance given it's a piezo material?
There was a similar antenna developed a few years ago that used a very thin metal membrane who movement was excited by HF magnetic field. Then bounce a laser off for the detection. It did not have a lot of gain, but had near zero noise (just quantum fluctuations) so was very good for receiving.
Soo there really will be voices in my head?
If you want news from today, you have to come back tomorrow.
Chu's limit appears to have been somewhat pragmatic in assuming that certain kinds of electrical circuits could not be feasibly realized.
Chu's Limit—a limit no more — 23 February 2017
The part I understand: built and measured.
Whoever did the write up is 180* out.. EM is the shorter wave ( hence the terms shortwave and microwave radio) and audio are the shorter waves .. but interesting concept
They're trying to kill everyone.
Correct. Improvements to batteries happen constantly but never make it to the people. To the people.
They hate batteries and have murdered people that made improvements to them.
Whoever did the write up is 180* out.. EM is the shorter wave ( hence the terms shortwave and microwave radio) and audio are the shorter waves .. but interesting concept
make that: Audio is the Longer wave (more physical distance between peaks).
If the wavelength is large enough, it becomes basically impossible to hide an aircraft with stealth shaping. So things like VHF radar will typically pick up stealth aircraft. So far the main issue has been that large wavelength antennas take up too much space precisely because of the limits explained in the article. If this stops being the case then VHF radars can be physically much smaller and portable and render stealth useless.
Audio is the Longer wave (more physical distance between peaks)
Avoid the term "audio"; 60 MHz acoustic waves (as described in this paper) are not audible.
Sound (in any normal medium) is far slower than light, so sound waves at some frequency are much shorter than radio waves of the same frequency. They're describing antenna that oscillate acoustically at millions of hertz; the same frequency as the EM waves being received, not thousands of hertz as in audible sound.
Maw! Fire up the karma burner!
They keep innovation from the people.
CH limit assumes a regular antenna, so it's irrelevent.
Part of shaping is that the reflected energy is AWAY from the transmitter. So you may see stealth designs that channel and eject in an upward manner where only aerial detectors may pick it up. There's also absorption. There could even be delays instead of hiding so that it may appear the target is further away from the receiver than it actually is.
For a site that publishes Science news, stating the wrong relationship for wavelength of EM [High Freq] vs Accoustic [Low Freq] is poor and the use of the word "astounding" to describe the speed of light make it's look like it was written by someone whose usual journalistic task is writing the Entertainment News.
For those of you who read about that absolutely crazy idea to send chip-scale (or chip "mass", they may be very thin objects like a film) interstellar probes riding on gigawatt beams of laser light (that would accelerate them to .2C in a few hours!), "maybe" this helps solve a problem.
How do they communicate with Earth?
This might allow them to RECEIVE (over interstellar distances?) a very powerful signal even if they are very tiny. The only problem is, I don't see how they could SEND back data; in addition to antenna size don't you need power? (My knowledge of physics is woefully inadequate to evaluate this). Short of them carrying self-replicating nanobots that could construct a large antenna at the destination using local materials (and local power), I don't see how even having a good antenna would allow them to get a signal over trillions of kilometers with even an enormous (space-based) receiving antenna. Does anyone know how the Starshot project intended on sending a signal back?
On the other, for LOCAL communications (say for chip sized probes scattered over a wide area), this might be a key breakthrough. Imagine a carrier spacecraft with a powerful communications subsystem settling into orbit around say Titan. It spews hundreds (thousands?) of these little chips which, with a little protection/good surface/weight ratio might be able to gently break into Titan's thick atmosphere. Then, once on the "ground" (or floating in the Titan seas) they could communicate back to the orbiter which would then relay the observations back to Earth. (How to keep them powered in the low light/liquid nitrogen temperatures is an exercise left to the reader).
Or this could be great for surveillance (or spying) or wildlife cameras (or spying) or ingestible sensors/cameras (or spying)
... make antennas for wireless communication ...
As opposed to antennas for wired communication?
It must have been something you assimilated. . . .
I must have misread something; converting EM to sound requires receiving the EM and thus a regular antenna, doesn't it?
Correct. Improvements to batteries happen constantly but never make it to the people. To the people.
TO THE PEOPLE!!
Self-replicating nanobots sounds a lot like science fiction. By the time we have them we probably have more advance technology in every other field too.
But let's assume that we can get something small to travel fast enough to reach another star in an adequate time.
That means that you can get it there and back in twice the time, so sending something to gather information and then collect it when it comes back is viable.
Pretty much any resolution and lensing would still be better than whatever information we can get now. A lot of planets in our solar system became known through naked eye observation.
We also don't need to use power during the travel so a chip-sized battery would be sufficient to taking a few pictures.
The problem is turning around. We would have to get very close to a large mass to turn around at speeds like that and getting too close to a star tends to make things break.
An alternative to self-replicating nanobots would be anything biological.
If we could use it to seed planets in other star systems that means that life won't be gone from this general area of the universe once the sun grows large enough to boil away the oceans and swallow earth.
It might not evolve to anything intelligent, but it's better than nothing.
Will there have to be 2 sets of antennas, a small one (mentioned in this article) for reception, and a another larger one for transmission? How does that reduce overall size?
Or, to keep it within audio frequencies with back-of-the-envelope calculation - a 60 Hz acoustic wave in air has a wavelength of roughly 5.7 meters. At 60 Hz, the EM wavelength is about 5 kilometers.
5000km actually...
Otherwise the AC power grid would be infeasible. One of the reasons that long distance links are increasingly DC is that once you hit 1250km with a 60Hz AC line, you have a quarter wave antenna and you start losing too much power to EM radiation.
All the examples sound really awesome. I am sure it will be used in reality to sell more crap to people.
It will be used to sell phones that are thinner, not with a larger battery capacity, but just thinner.
It will be used on marketing things we have not thought of yet. And it will be used to monitor us, so the companies know us even better and can sell even more stuff.
The future is awesome.
Don't fight for your country, if your country does not fight for you.
How do they communicate with Earth?
Long distance RFID, obviously.
Correct. Improvements to batteries happen constantly but never make it to the people. To the people.
(STORED) POWER TO THE PEOPLE!!!
Wanna buy a shirt?
https://www.redbubble.com/people/stealthfinger/shop?asc=u
So, next to feeling the EM waves of my WiFi router i will soon also be able to hear them.
I wonder what "they" will tell me to do....
Why are other peoples sig's always more witty ???
The antenna is 2 stage - it picks up the EM waves which essentially get converted into vibrations of the same frequency which are then converted in electircal signals. Ok, I get that. But I don't get how the EM waves make it vibrate in the first place and surely if the antenna is normally far too small to intercept the waves of a given frequency they'll just pass it by and nothing happens?
I'm obviously missing something here but RTFA article doesn't help and the nature document is a bit over my head. Can anyone explain whats going on in laymans terms?
While it is true that audio frequencies have longer wavelengths than radio, acoustic wavelengths are 100,000 times shorter *at the same frequency*. This is because the speed of sound in a solid is 100,000 times slower than the speed of light. A 1 gigahertz wave travelling at the speed of light (300,000 km/s) is 30cm long. A 1 gigahertz wave travelling at the speed of sound in a solid (3 km/s) is 0.0003 cm long.
Astounding? That is slow as F*ck!
Ok, how do I go about making an antenna like this for use on the RadioHam 136KHz band?
But really, lets start using these to shrink our ham radio rigs.
So who else read this and wondered if this could lead to electronically adjustable phased arrays to detect signal direction and increase gain?
When will I be able to pick up such a TV antenna at my local Radio Shack?
Have gnu, will travel.
"EMf=Soundf, then That means that that for any given signal frequency, the antennas can be much smaller." Wavelength is length for EM or sound, which decides antenna length.
You see, wire telegraph is a kind of a very, very long cat. You pull his tail in New York and his head is meowing in Los Angeles. Do you understand this? And radio operates exactly the same way: you send signals here, they receive them there. The only difference is that there is no cat.
Have gnu, will travel.
Smoke signals, or at least the interstellar version of them. There is more than enough light coming from a star, all you need to do is attenuate that in some way. For example, block some varying portion of the light using the combined area of the solar sails of a bunch of the star wisps. That variation over time encodes a signal.
Other than that, there is also the possibility of sending the signal from a certain location, which will use the star as a gravitational lense, amplifying a normal radio signal by focusing more photons at the target (Earth in this example). So you need to have say, Proxima Centauri between you and Earth and be at a sufficient distance so that Earth intersects the focal line of the gravitational lense.
That's a 50dB gain for an electrically small antenna in a domain where tenths of a decibel gains are considered advances. This is a quantum leap for antenna science.
Seriously, this should allow for nanobots and better spying gear.
I prefer the "u" in honour as it seems to be missing these days.
Can't we keep the antennae the same size but get 100% more reliable signals in and out of them?
joking
Do not meddle in the affairs of geeks for they are subtle and quick to anger
Pretty much the same difference in error as saying pi is 3.14
LTE Watches.
This story doesn't make much sense. Radio waves have only so much energy per cross-sectional area. If you make the antenna 100x smaller in one dimension, it's intercepting 10,000 times less energy. Also the conversion from acoustic to electricity is going to be inefficient and problematical at best. This sounds really fishy.
https://cdn.vox-cdn.com/thumbor/PJMIHVgpAHnqtIgrMb4hcTlQzes=/0x4:350x237/920x613/filters:focal(0x4:350x237):format(webp)/cdn.vox-cdn.com/uploads/chorus_image/image/47632113/zoolander-tiny-phone.0.0.jpg
XD
One of the ideas for this is to use the sail as the antenna. You only really need a few bits per second to transmit meaningful measurements.
A charged sail can make use of both the stellar and interstellar charged medium for propulsion. In the Starshot project they will be concentrating an array of powerful lasers at a reflective sail. If properly shaped, this can be focused back as a signal. It might even be so little as changing the polarization of the few photons making it back.
An alternative scheme uses energy from the beam partially absorbed by the material of the sail to power a transmitter. But this idea face issues with major decrease in acceleration.
Can these active-coupled acoustical antenna could improve the noise-floor for a receiver on the launch-side? If so then a much weaker transmission from the probe is all you need.
But like other powered antenna systems, this acoustical coupled one still needs power. Power on anything micro- or nano- is at a premium. No place to store it. Usually have to get it from your environment. Just like biological cells. But at least we'd be shining a big fricken laser beam right at the probe.
I'm fairly certain that an acoustic signal cannot be sent through space...
At 10 KHz, the audio/acoustic wavelength is measured in inches or fractions of an inch. A 10KHz radio wave is VLF, an EM antenna 1 wavelength long would be measured in miles or fractions of a mile.
I once saw an EM antenna that operated at approximately 10 KHz, it was indeed a good fraction of a mile long, and a a thousand feet or more up in the air, often in the clouds. On that day they had diverted their transmitter power to a large dummy load, consisting of a gymnasium sized building full of racks of power resistors. You could HEAR the signal in that room since the resistors and racks were vibrating at 10 KHz. This was at the Omega navigation station in Haiku valley near Kaneohe, Hawaii. It is abandoned now and has been vandalized, but the building can be seen if you look to the right from the H3 freeway before going through the tunnel, Honolulu-bound.
Comment removed based on user account deletion
You really need to start reading TFA before opening your pie hole.
That's only correct in a vacuum. In anything else, including air, it is slower.
the *single* lab unit is about 0.2 mm in diameter and has a gain of -18dBi.
An off the shelf Johansen ultra micro ceramic antenna for the same WiFi band has +1 dBi gain and is 0.5x1mm and costs about 25 cents in qty 10,000 from various online retailers.
The size of the Johansen unit is standard 0402 and designed for automatic pick and place assembly. I'm sure you could make one smaller.
So, let's see, 100 times less efficient and 1/5th the size. Not quite a world beater, is it?
SHUT UP!!! i'm trying to download a web page!!!!