Radio Waves• What are radio waves? They are a type of electromagnetic radiation that have wavelengths longer than infrared light, they also send frequencies over long distances or short distances depending who and where you are sending them too.• Radio waves are used for mobile radio communication as well as broadcasting, computer networks and many more appliances. Some of the technologies that use radio waves are mobile phones, televisions, Bluetooth and wireless connections.
Radio Communication• For radios to receive any sort of signal, a radio antenna must be used from AM/FM radio stations. Yet this means a radio tuner is needed to tune in to an individual frequency as the antenna can pick up hundreds of radio signals at one time.
Uses• Radio waves are the lowest frequencies in the electromagnetic spectrum and are mainly used for communications in the modern technological world. They are divided into...• Long wave: 1-2km in wavelength, the radio station ‘Atlantic 252’ broadcasts this.• Medium wave:100m in wavelength, BBC Radio 5 and other ‘AM’ stations use this.• VHF: Stands for ‘Very High Frequency’ and has wavelengths of around 2m. This is where radio ‘FM’ stations can be found such as Radio 1.• UHF: Stands for ‘Ultra High Frequency’ and has wavelengths of less than a metre. Used for Police radio systems and television transmissions.
Mobile Devices and Television• Radio waves have the longest wavelengths in the electromagnetic spectrum. These waves can be longer than a football field or as short as a football. Radio waves do more than just bring music to your radio. They also carry signals for your television and cellular phones.• The aerials on your TV sets receive the signal, in the figure of electromagnetic waves. That is then broadcasted from the television station, therefore displayed on your television screen.• Cable companies have antennae/aerials or dishes which receive waves broadcasted from your local TV stations. The signal is then sent through a cable to your house.• Mobile phones also use radio waves to transmit information. These waves are much smaller that TV and FM radio waves.
How do we ‘see’ using radio waves?• Space objects, such as planets and meteorites, giant clouds of gas and dust, and stars and galaxies, emit light at many different wavelengths. A small amount of light they give out has very large wavelengths - sometimes as long as a mile!. These long waves are in the radio region of the electromagnetic spectrum.• Because radio waves are larger than optical waves, radio telescopes work differently than telescopes that we use for visible light. Radio telescopes are dishes made out of conducting metal that reflect radio waves to a focus point. Because the wavelengths of radio light are so large, a radio telescope must be physically larger than an optical telescope to be able to make images of comparable clarity. For example, the Parkes radio telescope, cannot give us any clearer an image than a small backyard telescope and that has a dish 64 meters wide.
Radio Wave Transmission• In total there are two main ways in which electromagnetic energy travels from a transmitting aerial to a receiving aerial. One way is by ground waves and the other is by sky waves. Ground waves are radio waves that travel near the surface of the Earth. Sky waves are radio waves that are reflected back to Earth from the ionosphere.
The importance of radio waves in modern society• Radio waves mutely transmit information all over the planet. Radio waves have now become the basis for almost all non-written communication and most wireless technologies. They transmit signals that carry pictures, data, music and conversations invisibly over long distances. Without technology based on radio waves, you might find your day-to-day life abnormal and not recognisable.• Many household products we consider necessary depend on radio waves. AM and FM radios, wireless networks, telephones, radio- controlled toys, television programming, garage door openers, all of these, along with countless other devices, depend on silent, invisible radio waves to work.• Despite their importance, many people have become concerned about the possible negative health effects of excessive radio wave exposure. Specifically, the alleged culprits seem to be cell phones, which transmit their voice and data signals over radio waves, and cell phone towers, which route and receive these signals.