Most current day cellphone antennas don't have phasing for any tuned directionality. There are hard limits to array size due to physics and phones are just ve

Most current day cellphone antennas don't have phasing for any tuned directionality. There are hard limits to array size due to physics and phones are just very small compared to yhe wavelengths they use. And then there is the general challenge of synchronizing the transmitter phase. There is only so much that can be done via GNSS. If cellphone frequencies were not filled with cellphones, it could make for a neat radiotelescope on receive.