1. THE USE AND IMPORTANCE OF
RADIO WAVES AND SIGNALS
BEYOND RADIO BROADCASTING
Melissa Symons P11259018

2. Radio waves and signals are used in a number of different
devices, and are in no way confined to radio
broadcasting.
Other uses of radio waves and signals include
 · Cordless phones
 · Garage door openers
 · Wireless networks
 · Radio-controlled toys
 · Television broadcasts
 · Mobile phones
 · GPS receivers
 · MRI
 · Satellite communications
 · Police radios
 · Wireless clocks

3. SOME EXAMPLES IN MORE DETAIL
Cordless Phones
A cordless telephone is a combination of a telephone and a radio
transmitter/receiver. There are two main parts- the base and
the handset.
The base and phone are attached by a standard phone wire
connection. The base receives incoming calls through the
phone line (as an electrical signal) and converts it to an FM
radio signal before broadcasting the signal.
The telephone reaches the radio signal, converts it back into
an electrical signal to the speaker where is it then converted
into sound.
When the person talks the system basically goes the opposite
way. The handset broadcasts your voice back through a
separate FM signal back to the base which then converts it to
an electrical signal once again and through the phone line to
the other party.
This is called a duplex frequency.

4. Wireless Networks
A computer's wireless adapter translates data into a radio
signal and transmits it using an antenna. Then a wireless
router receives the signal and decodes it. The router sends
the information to the Internet using a physical, wired
connection (Ethernet)
This process also works in reverse(much like the cordless
phone) , with the router receiving information from the
Internet, translating it into a radio signal and sending it to
the computer's wireless adapter.
Wi-Fi has a lot of advantages. Wireless networks are easy to
set up and don’t cost much.
They transmit at frequencies of 2.4 GHz or 5 GHz. This
frequency is much higher than the frequencies used for cell
phones and walkie-talkies. The frequency being higher
allows the signal to carry more data.

5. Television
Different channels on a television use different frequencies (
carrier waves) and television receivers are designed so that
they can tune into a certain frequency at a certain time and
ignore other signals.
The radio signals received by a TV antenna are normally weak
and so have to be amplified, before being demodulated
through a tuner. The tuner produces electromagnetic waves
of the same frequencies as the carrier waves ( used to
broadcast channels)
Signals are sent to the antenna, which then sends the signal
out into the air as electromagnetic waves. The receiver
receives the waves and demodulates the signal before
recreating the original sounds/ images.

6. MRI (Magnetic resonance imaging)
Radio frequency (RF) energy has been used in medical
treatments for over 75 years
Radio waves are used in MRI scans to give 3D images of
the body. The magnet in the scanner causes all the
protons in the body to align, a radio wave pulse causes
the protons to move out of alignment in different
directions, generating the 3D image and giving a doctor
the ability to look at tissue, bone and fluid inside a
patient. Once the Radio wave pulse is turned off the
protons realign.

7. Radio controlled toys ( e.g. Cars)
The transmitter sends a signal over a frequency to the receiver in the toy.
The transmitter usually has a 9-volt battery, that provides the power for
the controls and the transmission of the signal.
The main difference between radio controlled and remote controlled toys
is that whilst the remote controlled toys have a wire that connects the
controller and toy, radio controlled toy s are always wireless.
 Most RC toys operate at either 27 MHz or 49 MHz
This pair of frequencies has been chosen for both these toys and other
basic consumer items, such as garage door openers and walkie-
talkies.
The way that the signal reaches the controls the car is similar to the
radios created in our lab sessions, inside the toy there is a circuit which
includes all the necessary equipment to pick up the radio signal.
“capacitors, resistors and diodes, as well as the IC that controls the
motors. The radio receiver consists of a crystal that oscillates at a
specific frequency, inductors and an antenna.”

8. Clearly radio waves are a large feature in a modern
society, branching much further that just as a form of
entertainment. Radio waves and signals control various
pieces of important technology that helps us stay
connected ( e.g. mobile phones, cordless phones and
Wi-Fi) but also keep us safe and healthy ( MRI scans
and police radio)
Eventually, I expect that an even larger proportion of
technology will become “wireless” and therefore
controlled by radio waves, and whilst this is positive in
terms of effectiveness and ease. There is also the issue
of loosing one’s privacy and the issues that would follow
if the “system” that we are already so reliable on were to
have a problem

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electromagnetic spectrum - Science Video. 2012. BBC - Learning Zone Class
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January 2012].
HowStuffWorks "Inside an RC Truck". 2012. HowStuffWorks "Inside an RC
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HowStuffWorks "What Is WiFi?". 2012. HowStuffWorks "What Is WiFi?".
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network1.htm. [Accessed 27 January 2012].
Radio and Television. 2012. Radio and Television. [ONLINE] Available at:
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