Radio waves are a form of electromagnetic radiation with the lowest frequency on the electromagnetic spectrum. They are used to transmit various forms of communication like TV, cell phones, radio stations, and more. Radio waves can be reflected by the ionosphere to travel long distances. There are different types of radio waves that are used for short, medium, and long-range transmissions. Radios and other devices receive radio waves through antennas and convert the signals into audio or video information to be played or displayed.

1. How Radio Waves Work
Myles Burke
P11253171
TECH 1002

2. Radio Waves
• Radio waves are found on the ‘electromagnetic
spectrum’.
• They have the lowest frequency on this spectrum.
• They are used to transmit; TV broadcasts, mobile
phone calls, police radio, AM and FM radio, even
radio controlled cars!
• The ‘ionosphere’, which is located between 45 and
250 miles above earth, can reflect radio waves and
bounce them across nations. This is how we hear
‘international broadcasting’.

3. There are 4 types of radio waves
• Long range – Local radio stations
• Medium range – Some AM stations e.g.BBC
Radio 5
• Very High Frequency – FM stations use this
range such as BBC Radio 2
• Ultra High Frequency – This consists of things
such as television transmissions and police
radio.

4. How radios receive and transmit radio
waves
• Radio frequencies are picked up by the radio
set through the air that the waves travel in.
• Your receiver will receive the available signals
whilst you ‘tune’ it and scan through the
stations.
• The radio will then interpret the signals and
‘demodulate’ them.
• Finally, your receiver will ‘amplify’ the sounds
it receives through either the speakers or
headphone socket.

5. Radio wave usage in other devices
• Early mobile phones use radio waves to
transmit information but the waves they use
are of a much smaller wave length than waves
used by TV and FM radio.
• With older television sets, the large antenna
on top of the station would pick up the signal
and turn in into visual information on the
screen. Most modern TV’s will use a dish that
picks up the signals through the sky.

6. • Radio telescopes use the large wavelengths of light that
are emitted by planets and large clouds of gas in space to
produce a higher resolution image of objects in space.
These special kind of telescopes turn the light produced by
stars to create a clear visual image of planets.
• RC Toy Cars use the transmitter (the control in your hand)
and the receiver (circuit board and antenna built into the
body of the car) to send a radio wave with a frequency of
around 27.9MHz that is picked up by the circuit boards in
the car. The amount of pressure applied on the trigger of
the controller sends an ‘electronic pulse sequence’ to the
integrated circuit in the toy car. The electronic pulse
sequence is decoded andsent to createthe appropriate
motor speed to the pressure applied to the trigger. And all
this is done in a matter of nano-seconds!

7. Wireless networks
• The 3 main types of ‘wireless network’ waves are;
radio waves, microwaves and infrared.
• Wireless networks include: routers for multiple
wireless internet access, remote controls,
wireless keyboards, mobile phones and wireless
radios
• Wireless communications allow easier access to
networks such as the internet and home
telephones (where you no longer have to stay by
the phone set connected by a wire).

8. Where different mediums are located on the
electromagnetic spectrum.

9. References
• http://www.howstuffworks.com/radio.htm
• http://www.cites.illinois.edu/101/wireless101
.html
• http://www.nrao.edu/index.php/learn/radioa
stronomy/radiotelescope
• http://www.darvill.clara.net/emag/emagradio
.htm
• http://www.howstuffworks.com/rc-toy.htm