6.6 - Radio Waves
Radio waves carry communication signals
- Radio waves are used mainly for communication - they carry television and radio broadcasts from one place to another.
- Radio waves have wavelengths longer than about 10 cm, and how a radio wave travels from transmitter to receiver depends on its wavelength.
- Longer-wavelength radio waves can be received over very large distances.
- The very short wavelengths used for TV and FM radio only reach a receiver in line of sight of the transmitter, because they don't bend or travel far through obstacles.
Bluetooth uses radio waves
- Bluetooth uses radio waves to send data wirelessly over short distances between devices (for example, a phone and wireless headphones).
- The wavelengths used are even shorter than those for TV and FM radio.
- The waves can pass through walls but are weakened as they do so, which keeps the range short and reduces interference between nearby devices.