How to make the phone generate a radio signal?

Question

Electronics

The phone can pick up a radio signal. Therefore, it has an antenna. Is there a way to make the phone generate a constant radio signal?

Answer 1

disassemble the phone.
connect to the cellular communication module, most likely there are no output points for connecting to this bus.
find in the public domain and study the control protocol of a particular module.
write a code that turns on the cellular module for a certain type of transmission.
debug the code.
receive the desired device.
....
get people from the State Committee for Radio Frequencies for unauthorized use of the radio frequency.
take a ready-made cellular communication module (sim800 and the like) the cradle from the GKRC will be the same.
if you play radio direction finding, then look in the direction of " fox hunting " and the like. ready-made kits were sold.

Answer 2

Do you mean "mobile"? Most likely - it is possible, but it will be necessary to seriously intervene in his program. In terms of labor costs - it may be more profitable not to mess with him.

I need to build a training setup with a rotating antenna for beamforming.

Frequency band set? "Mobile" 1.8 GHz fit exactly?
Is this a learning task or a practical one? And that is, CAD's on antennas.
PS Do you have an anechoic chamber? Or, at least, a "clean field" of 300x300 meters? Otherwise, the result will be doubtful even for educational purposes.