The purpose of an RF modulator is to ensure that the signal provided by the carrier can travel from place to place. There are three primary types of modulation that accomplish this task.
Radio frequency, or RF, modulation, while formerly used to describe frequencies of a certain bandwidth, is now a term used to describe various wireless signals. The process of modulation relates to how the signal is carried from one place to another.
Amplitude modulation, or AM, involves changing the signal's intensity and was the first method of sound broadcasting. Frequency modulation, or FM, involves changing the frequency or amount of signal. Phase modulation, or PM, involves changing the phase of the carrier. Both FM and PM are known as angle modulations that do not involve changes in amplitude.