Using Electromagnetic

Radiation to Communicate

(Tying it all together!)

In the beginning...Most of our everyday communication

starts off as sound waves.

These are NOT electromagnetic radiation – sound waves are mechanical and need a medium to move through.

To make long distance communication possible, we need to convert the sound waves to electromagnetic radiation.

Label the picture with the part of the spectrum used for each

communication device

Bandwidth In electronic communication, bandwidth is the

width of the range (or band) of frequencies that an electronic signal uses on a given transmission medium.

Bandwidth is expressed in terms of the difference between the highest-frequency signal component and the lowest-frequency signal component. It is measured in Hertz.

A typical voice signal has a bandwidth of approximately 3 kHz and an analog television broadcast video signal has a bandwidth of 6 MHz

The Fight for Bandwidth

Go to the following websites: http://online.wsj.com/article/

SB10001424052748703574604574499730302393274.html

http://communication.howstuffworks.com/telephone6.htm

Use the information (and any other information that you find) to answer outcome 25

Discuss problems produced by the limited range of the electromagnetic spectrum available for communication purposes.

The waves involved

http://www.brainpop.com/technology/communications/cellphone/

http://www.brainpop.com/technology/communications/radar/

How a Radio Works

http://www.brainpop.com/technology/communications/radio/

AM FM

Applications of ReflectionPlane mirror:

Concave mirror:

Convex mirror:

Ionosphere:

A “long answer” questionDescribe ways in which applications of

reflection of light, radio waves and microwaves have assisted in information transfer.