09-10-2012, 03:44 PM
ALL INDIA RADIO PRSAAR BHARTI
ALIGARH COLLEGE OF ENGINEERING AND TECHNOLOGY.ppt (Size: 2.35 MB / Downloads: 64)
INTRODUCTION OF AIR
Radio is the transmission of signals by modulation of electromagnetic waves with frequencies below those of visible light.
Radio is based on wireless communication or setellite communication.
In this era of technology due to need of wireless communication, A national service was planned and developed by the Prasar Broadcasting Corporation of India.
PRINCIPLE OF AIR
Transmitting
A radio wave carries information signal; Signals are converted into electrical signals. A carrier wave is then produced from the modulation. The wave is then amplified, and sent to the antenna that then converts signal into an E.M. wave.
Receiving
An antenna on receiving the signal send it to the receiver this then converts the electrical signal sends it to the amplifier either a speaker/headphones jack this is then converted into a sound wave.
Why FM is better then AM
Here is an example of both FM modulation and AM modulation you can see from the image that AM is much looser than the FM signal meaning that less data can be sent at one time as it isn’t compressed.
The reason for the difference in sound quality as a lower bitrate must be sent across the wave.