Answer:
a modulator
Step-by-step explanation:
Modulation can be defined as the conversion of digital signals into an analogue signal while transmitting it over a line. Similarly, demodulation is the conversion of analogue signal into a digital signal.
AM is an acronym for Amplitude Modulation and it's refers to a process that is typically used for coding sounds such as voices and music for transmission from one point to another.
On the other hand, FM is an acronym for frequency modulation used for the propagation and transmission of sound waves.
Basically, these two forms of modulation are used for broadcasting in radio transmission.
In Radio transmission, a modulator is an electronic device that is designed to superimpose a low frequency information onto a high frequency signal for transmission. Also, the high frequency is typically the carrier in the radio transmission process.