What are Radio Waves?Radio waves are a type of electromagnetic radiation. They can have wavelengthsthat are very long compared different types of electromagnetic waves likeinfrared or gamma. In fact, they are the longest type of electromagnetic wave andtravel at the speed of light.Radio waves were discovered over 100 years ago and nowadays they are almosttaken for granted, this is because radio waves do not only provide us with radiosignals/frequencies but they can also carry signals that our televisions andmobile phones can use.
What do Radio Waves do?Radio waves transmit different sorts of information. This information could bein the form of music, pictures and/or conversation, this is invisible data and iscontained in a radio wave/s. If radio waves did not exist it would be impossibleto transmit and receive information as easily, if at all.Radio waves have become increasingly useful with the rise in wirelesstechnologies. Television and mobile phones are just a couple of things that useradio waves. Other things that radio waves transmit signals for are: Wirelessnetworks, GPS receivers, wireless clocks and even small things like garage dooropeners.
The Basic Radio Wave StructureRadio waves all have the same basic structure with wavelength and amplitudebeing the only things that change if and when a radio wave is modulated insome way, this could be with sound or other data.The radio wave diagram below shows an unmodulated radio wave structure. Allunmodulated waves look very much the same. Amplitude
Different Radio Wave StructuresRadio waves can be modulated. There can be amplitude modulation (AM)waves or frequency modulation (FM) waves.The radio wave above is an AM radio wave. When sound is added to an AMradio wave the amplitude (height) of the wave changes giving the wave a morecurved look. However, the wavelength stays the same.The radio wave above is an FM radio wave. When sound is added to an FMradio wave the wavelength (space between waves) changes giving the wave amore varied wave structure, however the amplitude of the wave stays the same.
Radio Waves in TelevisionRadio waves in television are like FM radio waves and not AM radio waves.Television stations do not switch off overnight, they play constantly giving usprograms to watch throughout both the day and night. This is only possiblebecause of the way the radio waves that are used in television travel. FM andTV radio waves travel in the same way – by using transmitters on the surface ofthe earth. Using transmitters like these means that, unlike AM radio waveswhich bounce off the ionosphere to travel around, there is little or nointerference or distortion to the waves. This gives us a better picture on ourtelevisions and it also means that our signal stays strong without the signalneeding to be boosted, even through the night.The diagram below show the line of television and FM radio waves.
Radio Waves in Mobile Phones So many people around the world own a mobile phone. Radio waves are extremely important in the make-up of a mobile phone, a mobile phone would not work if radio waves did not exist. When people use their mobile phones to ring people for a conversation there is a transmitter takes the sound of your voice and encodes it onto something known as a continuous sine wave (a sine wave is varied continuously and radiates from the mobile phone’s antenna throughout space). When the sound has been encoded on to a sine wave, the transmitter inside the phone then sends the sine wave’s signal to the antenna, this then sends out the signal. Therefore creating The ability to have conversations on a mobile phone, without wires or any other complications. Mobile phones can lose signal when the radio waves are interrupted, This is especially noticeable when travelling in a car or on a train when tunnels distort the signal and conversations can be cut off.
References Cyber College. Film, Radio and TV [WWW]. Available from:http://www.cybercollege.com/frtv/frtv017.htm [Accessed 29/01/12] Google Images > Blog [WWW]. Available from:http://blog.sarmento.eng.br/?paged=4 [Accessed 29/01/12] How Stuff Works. Cell-Phone Radiation [WWW]. Available from:http://electronics.howstuffworks.com/cell-phone-radiation1.htm [Accessed 29/01/12] How Stuff Works. Radio [WWW]. Available from:http://www.howstuffworks.com/radio.htm [Accessed 28/01/12] The Electromagnetic Spectrum. Radio [WWW]. Available from:http://science.hq.nasa.gov/kids/imagers/ems/radio.html [Accessed 26/01/12] The Electromagnetic Spectrum. Waves [WWW]. Available from:http://science.hq.nasa.gov/kids/imagers/ems/waves3.html [Accessed 26/01/12] Wikipedia. Radio Waves [WWW]. Available from:http://en.wikipedia.org/wiki/Radio_waves [Accessed 26/01/12]
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