Modulator (noun)

1. A device or system that modulates or adjusts a wave or signal.
2. A person or thing that modulates or regulates.

Origin:

Late latin modulator, from latin modulatus, past participle of modulare, to regulate, from modulus, a measure.

Examples:

1. The modulator is used to adjust the frequency of the radio wave.
2. The modulator changes the amplitude, frequency, or phase of an electrical signal.
3. The modulator is an essential component in any radio or television transmission system.
4. He was a skilled modulator of his voice, able to change its tone and inflection for effect.
5. The modulator is used to ensure that the transmitted signal remains within certain limits.