Radio Waves Essay, Research Paper

Before beginning our research

on radio waves, to us, radio waves were just

waves going through the atmosphere, carrying

sound from one place to another. Those were our

ignorant days! We did not realize the complicated

terms and theories involved. In the following

report you will see how we advanced in our

knowledge of radio waves, and we hope it will do

the same for you. Radio waves are a combination

of two kinds of electric vibrations. Audio

frequency waves, which represent voice and other

sounds and radio frequency waves, which carry

audio waves after being combined with them. Two

examples of broadcast waves are AM waves and

FM waves. AM which stands for amplitude

modulation, is a broadcasting method in which the

carrier waves (carry the sounds of a program) are

changed to match changes in the audio frequency

waves. These are electric waves that represent the

sounds of a radio broadcast. FM stands for

frequency modulation and these waves, that go

skyward, are not reflected. Instead, they pass

through the atmosphere and go into space. AM

signals, however, reflect off the atmosphere and

travel back down to earth, causing broadcasts to

be received at a much greater distance than FM

signals. Since FM travels all the way to space and

it does not bounce off the ground it does not

create as much static as AM does. Radio waves,

which travel at the speed of light, cannot be seen,

heard, or felt in any way. When you listen to the

radio, contrary to what some think, you are

hearing the receivers pick up the waves and turn

them into sound. Three more types of radio waves

are; ground waves, ionospheric waves and

tropospheric waves. Ground waves travel from

the antenna along the surface of the earth.

Ionospheric waves, otherwise known as sky

waves, are made up of radio waves that come

from a transmitting antenna and go into the sky.

The ionosphere is the region of the rare field and

ionized atmosphere around the earth, from 50 to

200 miles. Last but not least are the tropospheric

waves. These waves are parts of the original wave

which is reflected into the troposphere, an area of

clouds and storms from 3 to 7 miles high. Radios

change sound into electrical patterns with

transmitters. In a radio transmitter, the circuit that

generates the high frequency AC current that

produces radio waves from an antenna, is called

an oscillator. Electrical patterns are then changed

into broadcast waves of electromagnetic energy.

The Kenelly-Heairside layer, found in a

transmission of a radio is now well known. This

keeps the energy spent by a shortwave transmitter

from escaping into space. This is why we are able

to receive shortwave from such a great distance.

Sound is changed into radio waves at a radio

broadcast station. The microphone, which is used,

changes the sound into an electrical current. The

transistors in an amplifier increase the strength of

the current. Then, the current goes into the

transmitter which is connected to an antenna. The

antenna sends out the radio waves. Although

broadcast waves are almost constantly

surrounding us, they can only be sensed by a

similar antenna. When you are turning the dial on

your radio to get a new station, you are actually

picking up a new broadcast frequency. The

frequency of a wave is the number of cycles that

happen in one second. Hertz is a unit used to

measure frequency. 1 Hertz is equal to 1 vibration

per second. There is a way to figure out the speed

at which a radio wave travels. It is by multiplying

the frequency of a wave by its wave length. The

wave length is the distance between peaks.

Diodes can detect radio waves. They were used in

radio broadcasting, but transistors have taken their

place. Radio waves are used in much more than

just radios. They are also used in cordless

telephones, television channels, and many

appliances in the average home. In conclusion,

radio waves have become part of everyday life,

and almost a necessity. Radio waves are just

another example of our advancing technology on

earth. As you have seen, radio waves are very

complex. We hope our report has enabled you to

further understand radio waves, it sure has for us!