Radio waves have the lowest frequency, longest wavelength and lowest energy out of the EM spectrum. They are the easiest to understand and is one of the earliest to be used for communications technology. It covers a broad area of the spectrum and are divided between short-wave and long-wave radio waves which have slightly different properties.
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What are they?
Radio waves can be produced both naturally by stars or artificially by vibrating electrons in a specific way in a transmitting source. the prime purpose of radio waves is to convey information from one place to another without having to use any physical links (e.g. wires).
Long wavelength radio waves are mainly used for basic information transmissions over vast distances, such as AM radio broadcasting, due to their ability to pass through blocking obstacles (they are not easily absorbed) and bend around the Earth's surfaces when transmitted (also known as diffraction). Long radio waves travel much further around the surface of the earth.
On the other hand, short wavelength radio waves cannot pass through large structures but are more easily reflected. signals can still be transmitted over long distances (not as much as a long wave) by beaming them upwards at an angle so they are deliberately reflected back by certain layers of the atmosphere and return to a different place on earth. This means that they are 'line-of-sight' based because they cannot bend around objects (diffract) as easily as long wavelength radio waves. Shorter wavelength radio waves also have a higher frequency, which means more information can be carried (e.g. FM waves).
AM radio waves can be tuned into nationally while FM radio can be generally accessed statewide.
Transmitting Information
The process of using radio waves in everyday communication technologies first requires a carrier wave to act like a messenger between the transmitter and receiver. The carrier wave is modulated with audio or visual signals and is sent. The receiving device picks up these signals and removes the carrier wave, leaving it with the audio/visual signal. These are then converted into sounds through speakers or pictures through screens.
Uses of radio waves
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