Emmanuel Techie-Menson

Student ID: P11280970

Radio waves used in media technology other than for radio broadcasting

The electromagnetic spectrum is a continuous range of wavelengths of radiation which all have different characteristics such as frequencies and intensities. These wavelengths are all emitted and absorbed by charged particles and are able to travel through space.

What are waves

‘Radio waves have the longest wavelengths in the electromagnetic spectrum therefore also have the weakest intensity.

Radio waves

•Amplitude modulation is defined as the multiplication of one time-domain signal by another time-domain signal. Its not possible to have amplitude modulation unless there are at least two different signals involved. The signals may be electrical in nature, or they can be vibration signals.

•The highest peak is the carrier frequency. The right-hand peak is the “upper sideband”, and has a frequency of the carrier frequency plus the modulating frequency. The left-hand peak or “lower sideband” has a frequency of the carrier minus the modulating frequency. The sidebands are sometimes called “sum and difference” frequencies because of their symmetrical spacing around the carrier.

What is amplitude modulation

Advantages Disadvantages

not efficient in its power usage

It is not efficient in its use of bandwidth, requiring a bandwidth equal to twice the highest audio frequency

An amplitude modulation signal is prone to high levels of noise because most noise is amplitude based

AM doesn't allow for additional services such as programme information or traffic news

It is simple to implement

It can be demodulated using a circuit consisting of very few components

AM receivers are very cheap as no specialised components are needed

No external aerials are needed

Amplitude modulation advantages & disadvantages

As technology has improved of the years, radio waves are not just used for radios but for other uses of media such as:

Television

Wifi

Mobiles

TVs use radio waves to receive both audio and visual signals which are then converted and brought up onto the screen.

‘The broadcast centre is the central hub of the system. At the broadcast center, the TV provider receives signals from various programming sources and beams a broadcast signal to satellites in geosynchronous orbit.

The satellites receive the signals from the broadcast station and rebroadcast them to Earth.

The viewer's dish picks up the signal from the satellite (or multiple satellites in the same part of the sky) and passes it on to the receiver in the viewer's house.

The receiver processes the signal and passes it on to a standard TV.’

Television

Radio waves carry data back and forth in every direction allowing wifi connection to take place. This is the latest update to wireless technology where accessing the internet does not require a cable. A router receives the signals and decodes them.

WIFI

It is now common for everyone to have a mobile phone as a way to communicate whether by calling, texting or email. Mobile phones use radio waves to receive signals back and forth from a station which is never more than 5miles away. A typical mobile can now receive around 800 frequencies across a city. The signals are received through its antenna where now a days doesn’t need to be as distinguished as before.

Recently, there has been a lot more caution taken place over the use of mobile phones as scientist have said that the radio waves sent to and throw from the phone can prove to be harmful to the brain cells in the long run.

Mobiles

•Now all of these technologies are a form presenting media. Radios, TV’s, Wifi and mobile phones have become essential to everyday life and communication. These are all used in places such as hospitals, police stations, schools and connecting onto the Internet for online media.

•Due to this the use of radio waves has been very beneficial

How have these waves helped us in our everyday life

•http://www.ehow.com/about_6633181_cell-transmission-_amp_-signal-work_.html

•http://www.bbc.co.uk/schools/gcsebitesize/science/aqa_pre_2011/radiation/the_electromagnetic_spectrumrev1.shtml

•http://www.darvill.clara.net/emag/index.htm

•http://www.azimadli.com/Vibman/whatisamplitudemodulation.htm

•http://nathanclarkecommunication.wikispaces.com/Range+in+electromagnetic+radiation

•http://www.radio-electronics.com/info/rf-technology-design/am-amplitude-modulation/what-is-am-tutorial.php

•http://www.satelliteonline.co.uk/how_do_we_receive_the_signals.htm

•http://www.ehow.com/about_6633181_cell-transmission-_amp_-signal-work_.html

•http://satelite.com/Install/UnderConstruction.htm

•http://www.google.co.uk/imgres?q=tv+radio+signals&um=1&hl=en&sa=N&rls=com.microsoft:en-gb:IE-Address&biw=1440&bih=805&tbm=isch&tbnid=iizLlzS3AId0iM:&imgrefurl=http://satelite.com/TVSatellites.aspx&docid=GF-TxQaZy8FHwM&imgurl=http://satelite.com/portals/5/satellite-tv-5.jpg&w=400&h=300&ei=BQgmT63FJMmDhQe0zqGBBQ&zoom=1&iact=hc&vpx=660&vpy=153&dur=42&hovh=194&hovw=259&tx=97&ty=113&sig=116631681022768198302&page=1&tbnh=146&tbnw=194&start=0&ndsp=28&ved=1t:429,r:3,s:0

•http://kashmirleader.blogspot.com/2011/07/make-srinagar-city-free-wifi-zone.html

•http://www.idevblog.net/2011_11_08_archive.html

•https://wikispaces.psu.edu/display/IST432SP11Team8/Overview+of+RFID

Bibliography