If you are referring to RFID chips, they are mini-transmitters, not antennae, and they can only be read within VERY short proximity (1foot or so) or
the chip.
A mobile transmits a signal to cell towers. Outside of a certain range, that mobile becomes useless. Now, look at the size of the antannae on the
mobile required to let it contact celltowers (I'm taking a rough guess here) 30km's away. So to use a mobile, you ahve to pepper the country with
cell towers every 30kms. Big, obvious things that stand 5-10m or more high.
Now take that mobile, & shrink it down to 14mm x 2.5mm (size of an RFID tag). That's a mighty small antennae & even smaller transmitter. It would be
necessary to make it as small as possible to extend battery life as long as possible. So now we've got a miniature device that can only transmitts /
communicate with devices within an anything from 1 - 4foot radius...last I paid any attention to my surroundings, there weren't any rfid towers every
3feet
..But I'm not an expert on this subject so feel free to prove me wrong