This document discusses radio waves and their uses. It defines radio waves as a type of electromagnetic radiation with wavelengths longer than infrared light that can transmit frequencies over long or short distances. Radio waves are used for technologies like mobile phones, Bluetooth, wireless networks, radio, television and more. The document describes how radio antennas receive signals and how radio waves are used in mobile devices and television transmission. It also discusses radio wave transmission methods and the importance of radio waves in modern society.

1. Individual Online Disseminated Presentation Publication
Radio Waves
Josh Hunt
P11265867

2. 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.

3. 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.

4. 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.

5. 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.

6. 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.

7. 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.

8. 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.