Electronic Communications

Engineers can use radio waves, microwaves, infra-red and light to transmit messages.

• Radio waves are used to send TV, radio and radar signals.
• Microwaves are used to send mobile phone and satellite signals.
• Infra-red rays are used by TV remote controls and night-vision cameras. Infra-red and light waves can also carry messages down optical fibres.

In analogue transmission, the shape of the radio wave changes with the beat of the music in the message.

In digital transmission, the sound or picture is converted into binary pulses of 1's and 0's that represent digital numbers.

Unwanted noise in digital signals can be cleaned up making digital transmission very good quality.