Frequency Modulation

What is Frequency Modulation?

A modulation scheme that encodes a signal by varying the frequency of a carrier wave while keeping its amplitude constant. Because most noise sources mainly disturb amplitude rather than frequency, this scheme is considerably more resistant to interference than amplitude modulation — exactly why FM radio sounds so much cleaner than AM.

The five clues

Engineerdle #70 described Frequency Modulation with five clues, revealed one at a time from hardest to most direct. Each clue points at a different property of the concept.

1. 01The rival scheme to a simpler, older modulation method.
2. 02Here, the carrier's amplitude stays fixed the entire time.
3. 03Instead, the information is encoded in how the carrier's frequency wanders.
4. 04It's considerably more resistant to noise, which mostly just adds amplitude, not frequency shift.
5. 05A modulation scheme where a signal is encoded by varying the frequency of a constant-amplitude carrier wave.