What are Radiowaves? <ul>Are a type of electromagnetic radiation, with the wavelengths longer than infra-red They also travel at the speed of light making them idea to travel through space for communications and satellites. Longer waves can cover the Earth very well, and even shorter waves can reflect from the ionosphere, part of the world's atmosphere, and travel around the world. They're used everyday from communication to television to medicine, where MRI's use radio wave frequencies to take images of the human body. </ul>
Radio in Broadcasting Radio has come a long way from when it was invented in the 1800's and found it's way in home in the 1900's. Mainly in how the way the waves reach your radio set at home. At first it was AM, Amplitude Modulation, where the height (amplitude) of the wave changed with each section of signal, however this leads to much interference and is mostly used for talk shows today. FM followed, more popular today than AM, where the frequency of the wave changes, this means there is less chance of interference because the signal can be decoded easier than AM. However, like most things, radio is now turning Digital. Which is meant to be better than FM however there have been many arguments against this, saying Digital Audio Broadcasing (DAB) has poor reception quality and even a time delay.
Telephones and Televisions <ul>The radio components of the telephone are similar in the way that they convert sound into electrical and send them off at a specific frequency. Another mobile receives at the same frequency and converts the radio waves back into sound to come out through the speaker. Televisions send their images in the same way though as an AM signal, the image is coded into radio waves, sent to an antennae, which picks up and helps resonate the frequency to make it stronger. The wave is decoded again to electrical to show the image and amplify the sound which is sent as an FM signal. </ul>
Wi-Fi <ul><li>A computer's wireless adapter translates data into radio signal and transmits it using an antenna.
A wireless router receives the radio waves and decodes it, then the router sends the information to the internet.
The radios used for Wi-Fi are similar to the radios used for walkie-talkies, mobile phones and other devices by converting the electrical signals into radio waves and then back again after.
They also transmit at a higher frequency allowing the signal to carry more data. </li></ul>
Navigation and Radar <ul>GPS uses triangulation to find out where you are in the world. GPS receivers do this by analysing high frequency radio waves from GPS satellites, because radio waves are electromagnetic energy they can travel up to 300,000 km/s in a vacuum, such as space. </ul><ul>Radar (Radio Detecting and Ranging) detects objects at a distance by bouncing radio waves off of them. They measure the distance from the object by measuring the delay of the echo. Navigational radars can scan an area 2-4 times a minute and are common on ships and air-crafts </ul>