3 ms·
Every frequency has a wavelength, as in a literal length of wave, which means a literal length of perfectly sized antenna. There's a formula. The right size f
by xen2xen1 4y ago
Every frequency has a wavelength, as in a literal length of wave, which means a literal length of perfectly sized antenna. There's a formula. The right size for FM (100mhz) antenna is something like 4 or 5 feet, but for wifi (2.4ghz), it's the size of a water molecule. That is not an accident, as the FCC did not lease 2.4 out permanently since water absorbs it, hence we can just plop an unregulated router/AP in our house. This paragraph is probably vague and generalized, and possibly wrong-ish towards the end, but close enough to aid general understanding.
- lolc 4y agoFluid water absorbs it very well, but the wavelength for 2.4 GHz is 0.125 m.
- usrusr 4y ago“length of a water molecule (at an accuracy of 1 ft)"
- galangalalgol 4y agoYeah antennas need to resonate, not just absorb. A litre of water wouldn't be a very good antenna at 2.4, but it would warm up due to absorption if it is a trong signal. A vhf antenna might make a terrible antenna at 2.4 as well, but it would also warm up in a strong enough signal. Don't belive me? Shove one in a microwave (please don't really).