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Communications Medicine Science Hardware

Engineers Discover How To Make Antennas For Wireless Communication 100x Smaller Than Their Current Size (sciencemag.org) 129

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.

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Engineers Discover How To Make Antennas For Wireless Communication 100x Smaller Than Their Current Size

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  • Lemme guess... we just proved the science and now just need to work out the small technicalities. Brain implants in 3-5 years.
    • Re: (Score:2, Funny)

      by Anonymous Coward

      Antennas in my fillings are receiving Ronald Reagan speeches about host files.

      APPS!

      • by mikael ( 484 )

        There was an urban legend that a man with a drill bit or titanium implant was able to hear BBC Radio 1 whenever he drove near a large national radio transmitter.

        • by Anonymous Coward

          "There was an urban legend that a man with a drill bit or titanium implant was able to hear BBC Radio 1 whenever he drove near a large national radio transmitter."

          Lots of people hear voices in their heads, no antennas or transmitters needed.

          We call them, mmmh, what's the word ... Mr. President.

          • Re: (Score:1, Funny)

            by Anonymous Coward

            There are many words for them my son, "progressives, liberals, antifa, blm, snowflake". You'll know them by their violent behavior and inability to co-exist with any who do not share the voices in their heads.

            • There are many words for them my son, "progressives, liberals, antifa, blm, snowflake". You'll know them by their violent behavior and inability to co-exist with any who do not share the voices in their heads.

              Remember "Taystee".

        • by Anonymous Coward

          Get near a large radio transmitter, and any chunk of metal will receive the signal to some extent. If it is AM, then demodulation practically happens automatically - so if any of the signal gets turned into audio - almost no matter how inefficient - you could get something hearable. They transmit kw/MW, but mW is enough for hearing.

        • by gnick ( 1211984 )

          There was an urban legend that a man with a drill bit or titanium implant was able to hear BBC Radio 1 whenever he drove near a large national radio transmitter.

          Lucille Ball was convinced that she picked up radio transmissions in her teeth. Music first and Morse code later IIRC.

    • by Anonymous Coward

      Brain implants is an unlikely application, but perhaps you will be able to listen to radio on your phone without having to use the headphone cable as antenna.
      At least one of the links provided plenty of information without being behind a paywall. Unfortunately I can't be bothered to read it.
      But since we all are here to complain about problems that we don't know if they even exists I'm going to say that to problem with this new technology might be that it is too narrowband to be usable.
      A lot of radio applica

      • "Brain implants is an unlikely application,"

        Why not, "Oath of Fealty" anyone? I would get one.

      • Re:3-5 Years (Score:5, Interesting)

        by jbengt ( 874751 ) on Thursday August 24, 2017 @08:29AM (#55074805)

        . . . problem with this new technology might be that it is too narrowband to be usable.

        Well, for what it's worth, TFA says:

        "In this work, the demonstrated ME antennas span a wide range of frequencies from 60MHz to 2.5GHz, which are realized by a geometric design of resonating plates that exhibit different mode of vibrations"

        and

        "It is notable that ME NPR antenna arrays with multiple frequency bands from MHz to GHz can be integrated in one wafer by designing the ME NPR with different lateral dimensions (or W), since the fr,NPR is inversely proportional to W27. This allows the broadband ME NPR antenna arrays on the same wafer, which compensates for the narrowband operation frequencies of ME antennas."

  • by rfengr ( 910026 ) on Wednesday August 23, 2017 @10:45PM (#55073449)
    Does it break the Chu Harrington limit? How is the noise performance given it's a piezo material?
    • by epine ( 68316 ) on Wednesday August 23, 2017 @11:24PM (#55073525)

      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 [phys.org] — 23 February 2017

      He was able to achieve this thanks to two novel advances: non-Foster circuits and internal matching. Non-Foster circuits are active, transistorized circuits that effectively create capacitors and inductors that are negatively charged, meaning the reactance is inverted to that of conventional capacitors and inductors. Coupling this technique with internal matching—embedding the antenna and circuit into one structure—allowed the electrically small antenna to achieve a broader bandwidth, while not sacrificing efficiency. An electrically small antenna is one in which the largest dimension of the structure is less than one-tenth of a wavelength. Most electrically small antennas have less than 1 percent efficiency, but Church was able to achieve an efficiency of 85 percent.

      The part I understand: built and measured.

      • by Tailhook ( 98486 ) on Thursday August 24, 2017 @12:05AM (#55073613)

        The Chu Limit applies to passive antennas. The antenna described in your citation isn't passive; that "non-Foster" term means it's an active antenna. The phys.org title implying some sort of breakthrough physics is click bait.

        • Re: (Score:3, Insightful)

          by Anonymous Coward

          The Chu Limit applies to passive antennas. The antenna described in your citation isn't passive; that "non-Foster" term means it's an active antenna. The phys.org title implying some sort of breakthrough physics is click bait.

          The acoustic antenna they design is passive and does not exceed the Chu limit, keeping in mind that the Chu limit accounts for the speed of propagation, i.e. light vs sound.

          From the Paper, "We note that the demonstrated ME antennas are pure passive devices, no impedance matching circuit, or an external power source was used during the measurement. And its maximum achievable bandwidth is within Chu–Harrington limit (Method)"

          The whole thing is really about their novel magnetic piezo material and device

  • Metal membrane (Score:5, Informative)

    by rfengr ( 910026 ) on Wednesday August 23, 2017 @10:49PM (#55073455)
    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.
    • Re:Metal membrane (Score:5, Interesting)

      by vtcodger ( 957785 ) on Thursday August 24, 2017 @03:08AM (#55073915)

      "It was very good for receiving'

      Same could be said for the ubiquitous ferrite loop antennae used for AM broadcast reception. They are magnetic field devices that can be quite small (a few cm) compared to medium wave wavelengths of several hundred meters. They are great for reception, but pretty much useless for transmitting. They also have very narrow bandwidth,. have two very sharp nulls in their reception pattern, and work progressively more poorly as the frequency increases.

  • Soo there really will be voices in my head?

    • "Soo there really will be voices in my head?"

      Only until the non-replaceable battery dies (or explodes).

  • Swap that ..... (Score:1, Informative)

    by IronOxen ( 2502562 )
    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
    • 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).

      • by Tailhook ( 98486 ) on Wednesday August 23, 2017 @11:47PM (#55073569)

        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.

    • Whoever did the write up is Doge.

      light speed -- an astounding 300,000,000 meters per second

      Doge did the write up.

  • by cheesybagel ( 670288 ) on Wednesday August 23, 2017 @11:41PM (#55073561)

    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.

    • by Anonymous Coward

      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.
    • by Anonymous Coward

      And sound goes at a few thousand meters per second... yeah it's rubbish allright.

      • by fisted ( 2295862 )

        And sound goes at a few thousand meters per second...

        Not in solids, generally.

        yeah it's rubbish allright.

        The real rubbish is your comment and its parent.

    • Re: (Score:3, Informative)

      by Anonymous Coward

      Or your reading comprehension is simply rubbish. They're using EM vs acoustic of the same frequency, that's kind of the point.
      And, since EM has the higher speed, it also has higher wavelength at a given frequency.

    • by martinX ( 672498 )

      When I read ... "an astounding 300,000,000 meters per second" I checked the source. "Science Mag". Maybe it should be Sciencey Mag.

  • by wisebabo ( 638845 ) on Thursday August 24, 2017 @01:07AM (#55073721) Journal

    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?

    • As opposed to antennas for wireless reception only would be my guess.
    • 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.

  • 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?
  • 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.

    • So the antennas are picking up ACOUSTIC vibrations, instead of EM signals. Acoustic vibrations travel at the speed of SOUND, not the speed of light. That means if you use a cell phone with this technology, then there will be HUGE latency issues, already worse than what cellphones have now.

      You would be better off just standing on your roof and SHOUTING to the person that you wanted to call.
  • Sooooooo (Score:4, Funny)

    by dr.Flake ( 601029 ) on Thursday August 24, 2017 @05:37AM (#55074235)

    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....

  • by Viol8 ( 599362 ) on Thursday August 24, 2017 @05:37AM (#55074237) Homepage

    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?

    • by Anonymous Coward

      Take the obgoodoo and the bogoodoo and you have a revolutionary new gizmo that only works in the lab and will never be used in real life.

    • Re: (Score:2, Informative)

      by Anonymous Coward

      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?

      Construction involves piezoelectric material, which changes shape according to the strength of electric field in which it is placed. It means that if you apply varying field, it will follow field changes with own shape change. The opposite holds true too: if you mechanically change the shape of an object having piezoelectric property, it will generate electric field.

      The antenna doesn't need to be placed across the whole wave, it just needs to resonate with the rhythm of the change: when it contracts because

    • They pick up the EM wave inefficiently (passively) at the start. It gets the antenna vibrating, which then increases its efficiency (now a non-Foster, active antenna) to thousands of times higher than normal.

  • by shaitand ( 626655 ) on Thursday August 24, 2017 @09:33AM (#55075151) Journal
    But really, lets start using these to shrink our ham radio rigs.
  • When will I be able to pick up such a TV antenna at my local Radio Shack?

  • Seriously, this should allow for nanobots and better spying gear.
  • Can't we keep the antennae the same size but get 100% more reliable signals in and out of them?

    joking

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