Radio waves are an important aspect in working of some electronic devices

1. Radio Waves
By ABIN SABU
S2ECE
ROLL.NO:2

2. What are Radio Waves and how do they
work?
• Radio waves are an unseen form of electromagnetic radiation which
fluctuates in wavelength from a millimetre to 100,000 km. This makes it have
the widest range on the electromagnetic spectrum.
• Marconi was the patent who first came up with the idea of wireless
telegraphy.
You can see that
radio waves take
up quite a lot of
range on the
electromagnetic
spectrum

3. Examples of Devices that use Radio
Waves:
• Mobile Phones
• Television
• Satellite Navigation
• Microwave

4. Mobile phones
• Mobile phones do use electromagnetic radiation.
• The type they use is Microwave.
• A transmitter takes your voice and encodes it onto a sine wave
• This signal is then transmitted to an antenna which then emits it into the
atmosphere
• These waves are then picked up by a mobile phone tower.
• The mobile phone network provider then sends this signal back to the
mobile phone

5. Television
• The typical television signal needs a bandwidth of 4 Hz
• The tuner in your TV removes the merged video and sound signal for that
channel from the radio waves received by the aerial.
• These radio waves have been sent by the broadcaster and then picked up by an
antenna.

6. Satellite Navigation
• Satellite Navigation devices use the Global Positioning System satellites
to locate your position it does this through three satellites.
• Each of these satellites transmit information being received from the
signal been given out by the sat nav device. It uses this information from
all three to come to a conclusion as to where you are positioned.
• Once it knows where you are it then has the complex task of finding the
shortest route to your destination.

7. Microwaves
• Microwaves work from the benefit of water molecules subjected to
electromagnetic waves.
• The water molecule is dipole meaning that one side is positively charged
the other being negative. The electromagnetic waves in a microwave are
in the frequency bandwidth of 2.5 GHz

8. Conclusion
• In conclusion, there are many types of radio waves in devices that we use everyday.
Some times these radio waves are considered to be harmful such as in mobile phones
and microwaves but other times they save lives with things such as the radars.
• Radio waves also prove to be very versatile and seem to have great uses in todays
world. Satellite navigation is a great example of how it has helped make our lives
easier. No more worrying about whether to keep your eyes on the road or the map.

9. THANK YOU