I read the article Google wants the US' wireless spectrum for balloon-based Internet. It says to use over 24 GHz frequency spectrum for communication.
Is it ever possible to generate that high frequency by using piezoelectric crystals? Or are they using a PLL frequency multiplier?
Even if it is possible to generate that high-frequency signal, and if you want to send 1 bit on every period of signal, there must be a processor that is working much more faster than 24 GHz. How is that possible on a balloon?