Tuesday, July 5, 2011

Radio Waves (Akhil, Heo Yub, Jake, Jonathan)

- Radio waves are made by various types of transmitters.
- Natural radio waves are caused by lightning, stars, sparks which is why there is an interference on the radio when there is a thunderstorm.
- Radio waves can reflect off the ionosphere (part of the upper most layer of the ozone layer) to travel around the earth.
- Radio frequency is used for medical usage, for minimally invasive surgery, like sleep apnea.

Four types of waves
- Long waves: around 1-2km in wavelength used to broadcast over long distances like in the united states from state to state.
- Medium waves: around 100m in wave length , usually used in AM stations
- VHF(Very High Frequency): around 2m in wavelength. FM radio stations in civilian aircrafts and taxis.
- UHF(Ultra High Frequency): wavelengths of less than a meter. Used for police radio communications, television transmissions and military aircraft radios.

FM vs AM Radio
-AM Waves are easily affected by weather and large objects between the radio receiver and transmitter.
-FM Waves are not very easily affected by weather.
-AM waves are preferred for transmitting over long distances as it follows the curvature of the Earth. FM waves travel in straight lines so are not that suitable for transmitting over longer distances

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