Communication Uses of Electromagnetic Waves

Electromagnetic waves are widely used to carry information. Different frequency bands are chosen depending on: distance; bandwidth; atmospheric transmission; antenna size; ability to penetrate materials; directionality.

Radio waves are used in: broadcasting; long-range communication; * some navigation systems.

Microwaves are important for: satellites; mobile phones; Wi-Fi; radar; * point-to-point links. Their shorter wavelength allows smaller antennas and more directional beams.

Infrared is used in: remote controls; short-range optical links; * some fibre-optic systems at suitable infrared wavelengths.

Optical fibres carry light pulses through glass or plastic fibres. Advantages include: high data capacity; low signal loss; * resistance to electromagnetic interference.