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Thread: New Chips Use Almost no Power to Transmit

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    New Chips Use Almost no Power to Transmit

    These chips could radically change IOT and other communications in that it that they are both low cost and consume almost no power by altering existing radio signals. This could be a radical game changer and advance the size and scope of IOT adoption and communications in general greatly. It will be interesting to see other technologies that harvest ambient power from different sources and how they start to advance. I see a whole range of ways of harvesting power of all types and with the power consumption of chips dropping at the same time the applications should expand at a geometric rate.



    https://www.technologyreview.com/the...most-no-power/

    First battery-free cellphone makes calls by harvesting ambient power

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    Blogger Bernard Murphy's Avatar
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    Arthur, reading the first article, they switched one step, analog to digital conversion in the communication path, to being based on harvested power. That is very interesting but it is far from making cellphones battery-free. Phones consume a lot of power even when not communicating, for example they burn power in transmission. Here you can't fight physics - power received at an antenna drops off with the square of distance to the antenna (for a practical sized antenna). If you put pico/micro-base-stations absolutely everywhere and rely on mesh networking, perhaps you could reduce required transmit power, but that seems rather a long way off as an economic possibility. More importantly, you would be trading reducing power need in mobile devices for probably a massive total power demand in zillions of pico/micro-base-stations. Doesn't seem like a good tradeoff.

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    Bernard, I think you mean the *second* article. They do say "The battery-free phone does still require a small amount of energy to perform some operations." In a real phone there are, of course, all kinds of things that take power, from driving the screen (which theirs doesn't seem to have) and the speaker (if they're harvesting the energy from that it really is a perpetual motion machine) to computations such as encryption and packet header compression.

    The first article says they avoid needing to power the transmitter by selectively reflecting radio waves that are already passing through space, a neat idea which no doubt works in the lab but I'm sceptical whether it would work well enough out in the world.

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    Blogger Bernard Murphy's Avatar
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    Good catch John - my mistake. And good added insight

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