What Is Frequency Modulation (FM)?

Frequency modulation (FM) is one of the oldest ways of encoding data. If you've ever listened to a song on the radio that sounds a little fuzzy, judders and jitters as it plays, that's an FM signal. It's pretty simple: You take an analog sound wave, or any other type of energy, and shift its frequency up or down by varying degrees. The frequency changes encode data onto the modulated signal—like the bit of fuzziness in your music. The trick is that this kind of encoding isn't just good at transmitting data; it also makes it so easily read by your ears! That's because when you change a sound wave's frequency up or down, it changes its pitch—and our brain is good at recognizing those changes in pitch so we can tell the difference between high notes and low notes. That means that when you listen to a song on the radio, your brain doesn't only hear all those frequencies—it also deciphers them into words and letters that make sense to us. That's why we can sing along with our favorite songs without even realizing it! Did you know that frequency modulation is the only way for radio transmission? No modulation method with a signal-to-noise ratio other than FM is the best way to minimize interference. Why should you care about reducing interference? Interference is BAD NEWS. It can cause your car to turn off while driving or your pacemaker to stop working while lying in bed at night. Interference also harms your brain—it can make it hard for doctors to read your EEG results or, even worse, cause people to listen in on your private conversations or read over your shoulder at work. Fortunately, frequency modulation makes all those issues go away!