Researchers discover battery-free technology which harvests power from radio and Wi-Fi signals for low-powered devices
Researchers discover battery-free technology which harvests power from radio and Wi-Fi signals for low-powered devices
Applications would result in less dependency on batteries in low-powered devices
cross-posted from: https://lemmy.ml/post/18426215
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Tale as old as time. And guess what will happen? Wifi signal strength will go down.
how exactly? What will physically happen?
Any receiving antenna is basically an energy harvesting device. Usually, it is specially designed to harvest just enough energy to actually receive the signal in order not to weaken the field. In the 2.4GHz spectrum, where WiFi and BT are at home, a sender is limited to 10mW of power. The more power energy harvesting devices draw from this field, the less will be available for other devices to actually receive the information.
Technically, an electromagnetic field of a frequency f will induce an alternating current in an antenna of length lambda/2 (or lambda/4 or even lambda/8, with less power received the smaller they get and lambda=wavelength=speed of light/frequency) that the receiver can "take out" at the antennas mid point and feed it into an amplification circuit.
Wouldnt the effect be very local? How far could the harvester affect the field? But i suppose it would be quite annoying if multiple people used something like that in densely populated area.