3 ms·
One problem with this that wasn't as much of a problem in the 1970s is RF interference. The 1970s designs and many other designs use 2.45 GHz, so it will interf
by gene-h 3y ago
One problem with this that wasn't as much of a problem in the 1970s is RF interference. The 1970s designs and many other designs use 2.45 GHz, so it will interfere with wifi and bluetooth, with bluetooth being more sensitive to interference.
How far does this interference extend? Thousands of kilometers from the receiver[0, see page 250]. Because the transmitter is far, the beam spreads out quite a bit due to diffraction and because the transmit power is gigawatts there's hundreds of megawatts of stray power. Making bluetooth headphones and bluetooth low energy tags work worse will probably make people angry.
Different frequencies could be used, but that requires allocating spectrum, which is a pretty difficult task politically. In the US, there are a couple bands in the sub-10 GHz range where power beaming works best that have few users. So it's not impossible, but still politically difficult.
[0]https://ieeexplore.ieee.org/document/9318744 https://ieeexplore.ieee.org/document/9318744
- mlyle 3y agoThis is a really good point. I know super narrow notch filters up in the gigahertz are difficult, but has anyone thought at all about how narrowband the power transmission could reasonably be? Because then at least notching would be possible to squeeze out adjacent spectrum.
- techdragon 3y agoThere are techniques. And generally speaking the bandwidth can be much narrower than the sort of things designed back then. Even a lot of modern systems are designed with less than state of the art tech for various reasons… reliability, cost, etc.
- mNovak 3y agoI bet the military would love/hate it (depending where deployed), because all that stray illumination would make for a perfect bistatic radar source. Suddenly many radars can be passive, and stealth techniques take a serious hit.
- wbl 3y agoNot really: you need to have some modulation to resolve position, not just angle.
- deleted 3y ago[deleted]