Technology
How does radio work?
Radio works by encoding sound onto invisible electromagnetic waves and broadcasting them through the air. A transmitter sends the waves out; your radio's antenna catches them and converts them back into the sound you hear.
See it in motion.
Watch a 2-minute animated lesson that shows exactly how radio works.
Step by step
- 1Sound is converted into an electrical signal.
- 2A transmitter rides that signal on electromagnetic waves.
- 3The waves travel through the air at the speed of light.
- 4Your receiver's antenna captures them and rebuilds the sound.
Frequently asked questions
- How does radio send sound through the air?
- It encodes the sound onto electromagnetic waves that a transmitter broadcasts and your radio receives.
- What's the difference between AM and FM?
- AM varies the wave's strength (amplitude); FM varies its frequency, giving clearer, higher-quality sound.
- Do radio waves travel at the speed of light?
- Yes — radio waves are electromagnetic, so they travel at the speed of light.