The broadcast of every radio and television programme involves the use of radio waves.Radio waves are the type of electromagnetic waves with the longest wavelengths.Radio waves are produced by passing an oscillating electric current through a long wire called an aerial.The frequency of the radio wave produced is the same as the frequency of the oscillating current.This allows radio waves of different wavelengths to be produced.
These radio waves have slightly different properties and are used for different purposes.Radio waves of different frequencies are used to broadcast radio and television.Several types of radio waves are used for communications.
Microwaves with different wavelengths have slightly different properties and uses. They are also produced in different ways Long-wavelength microwaves are produced by aerials in a similar way to other radio waves. These types of microwaves are used for communications.Microwaves are used to send communications signals to and from satellites. They also carry signals for mobile phones, wireless computer networks and personal digital assistants