>>11861168OP here.
t.b.h., I had done some "research". I'm not an EE, phycisist or anything related (though I wish I was...), so take this with a ton of salt:
from what I've read, the problem is not the length of the antennas, the real problem is having diodes that are fast enough to let THz waves pass, or at least having ways to extract those high frequency electrons.
also, regarding the use of DVDs to produce graphene: I guess this could be really helpful:
https://pubs.acs.org/doi/10.1021/acssensors.8b00340 https://www.youtube.com/watch?v=5bqujaldaCQ>>11861301how efficient would antennas be? wouldn't efficient antennas be able to recover more than 50%?
https://en.wikipedia.org/wiki/Rectenna says
>RF rectennas are used for several forms of wireless power transfer. In the microwave range, experimental devices have reached a power conversion efficiency of 85-90%.sure, that's for a given frequency, and not a range.. but still.
