• bufalo1973@lemmy.ml
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    20 days ago

    Imagine you are with a friend on the beach., side by side on the water and a big wave comes. Do you fell less pressure because your friends is by your side?

  • CanadaPlus@lemmy.sdf.org
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    19 days ago

    How side-by-side are we talking? If the antennas are closer than their size, yeah, it won’t necessarily work the same way because they’ll act like one antenna. If they’re too far apart for “near field” effects (or if your antenna was tiny relative to the wave to start with, like with AM radio) it won’t matter, because the wave in question will just kind of ooze around any obstruction, and received power will just go with inverse square of distance to source again.

    In practice, it’s unlikely to matter so much how loud the signal is, because (unless you’re using a crystal radio) you are definitely going to amplify it quite a lot before it’s useful, anyway. More of concern is how loud it is relative to any random noise that’s present, which is not so dependent on antenna area.

    Edit: I suppose if it’s between you and the source, it will dim the signal a tiny, tiny little bit. Not the way a bigger thing can cast a shadow, though; think more like a slightly dirty lens.

  • 🇰 🔵 🇱 🇦 🇳 🇦 🇰 ℹ️@yiffit.net
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    20 days ago

    Radios receiving signals don’t just siphon the signal off lol

    What you’re asking would only really happen with wireless Internet service and it’s not because of the wireless signal, but because the overall bandwidth diminishes the more people connect to it.

      • YourAvgMortal@lemmy.world
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        20 days ago

        It’s like solar energy. You either absorb it with a panel, or it goes to “waste”. You’re not really stealing it from someone else, as long as you’re not getting too much in the way

        • VirtualOdour@sh.itjust.works
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          19 days ago

          Usong your analogy i think Ops question was really if you have a stack of transparent solar panels will the panel below get less power and the answer is of course it will. If one antenna is behind another there will be a small reduction in the power of the signal reaching it, probably very small but with enough of them you could theoretically construct a faraday cage of sorts.

        • CanadaPlus@lemmy.sdf.org
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          20 days ago

          The current produced in the antenna does (induce a field which goes on to) cancel the wave out a bit. Not enough to be noticeable in the far field, for a normal-sized antenna, but some. Conservation of energy, right?

      • CanadaPlus@lemmy.sdf.org
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        20 days ago

        Yup. It’s typically amplified quite a lot in the receiver, and the vast majority of power transmitted never is received, so it doesn’t usually matter, but it’s not a dumb question.

  • piecat@lemmy.world
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    19 days ago

    Depends. If the antennas were resonant dipoles placed some fraction of a wavelength away from each other (1/4 wave away), you may get some cancellation of the signal.

    Look up the “yagi uda” antenna, it’s the classic rooftop tv antenna. The elements are spaced by fractions of a wavelength to achieve directivity. One single element is driven, the others are just resonant lengths of wire.

  • VirtualOdour@sh.itjust.works
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    19 days ago

    People are answering what you asked but what you probably mean is in a 2d world where two antenna are perfectly in line with the transmitter will the first absorb some of the signal - yes it will, just like two wind turbines in a line it’s absorbing the energy from the medium and using it to do work.

    It’s not always so simple, it might spit some of if out too if it doesn’t have anywhere else for it to go and it’ll do this in a certain pattern which can, depending on the distance and arrangement ,increase the signal received by the second one. This and similar principles are why you see so many odd shapes for antenna designs such as the many bars on a TV antenna which make it more directional.

  • NeptuneOrbit@lemmy.world
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    19 days ago

    You and the person on a chair on the beach next to you will both get sunburnt. In the same way, radio waves washing around your house or car interacts with everything, antenna or not.

  • Sims@lemmy.ml
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    20 days ago

    A laymans opinion on the challenge: Waves lose energy, and the exact placement of antennas will matter. I don’t know what the mechanism is called, but we don’t place wind turbines right next to each other. That is afaik because each turbine takes some of the energy out of a larger chunk of the wind-wave in an ‘bubble’ around it, so we place them with optimal distance according to efficiency of that mechanism. If I’m right the effect will probably be minimal. Anyway, just a stab at an interesting thought…

    • CanadaPlus@lemmy.sdf.org
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      20 days ago

      Yep. It’s called near field and far field in radio. In the far field you can approximate it as a beam from the transmitter, while in near field it’s magnets and things can absolutely interact. You never want to put up a stand-alone antenna in the near field of something conductive. Those big tower antennas actually incorporate the ground as a critical part of their design, because of that and the non-negligible conductivity of ground water.