Transceiver and RF Emissions (Unintentional)
I think RF refers to Radio frequency. Smart phone emissions are electromagnetic waves that has a specific frequency.
examples of electromagnetic waves would be: ultraviolet, light, infra-red, microwaves and radio waves. They are all the same, They are composed of photons. but they have different frequencies. and The behaviour of a specific wave depends on its frequency. so, RF emissions are light that we can not see because its frequency is low (it has low energy) and it can not stimulate the optic nerve. RF can pass through wall and they see walls as transparent materials and they can pass through it, They are like light when it pass through glass and see it as transparent material. That's why we use RF for transition of data.

Transmitter is different from transceiver. The word transceiver means a circuit that contains transmitter and receiver together. I don't know how a smart phone receiver actually work but in general, to transmit radio waves you have to build and oscillator or resonator that produce an AC current with a specific frequency (for example 1 MHz). This rapidly changed current generates radio waves that have the same frequency. To receive this signal you have to build another oscillator or resonator that oscillate at (1 MHz) so that it receives all waves that have 1 MHz frequency.

To measure these waves there are RF meters and other devices, you can see some examples here: http://www.lessemf.com/rf.html