Frequency modulation

“ When the frequency of carrier wave is changed in accordance with the intensity of the signal, it is called frequency modulation”.

• Here the amplitude of the modulated wave remains the same ie carrier wave amplitude.
• The frequency variations of carrier wave depend upon the instantaneous amplitude of the signal.
• When the signal approaches positive peaks as the B and F, the carrier frequency is increased to maximum and during negative peak, the carrier frequency is reduced to minimum as shown by widely spaced cycles.

Advantages of FM

1. It gives noiseless reception.
2. The operating range is quite large.
3. The efficiency of transmission is very high.

Demodulation

The process of recovering the audio signal from the modulated wave is known as demodulation or detection.

At the broadcasting station, modulation is done to transmit the audio signal over larger distances. When the modulated wave is picked up the receiver, it is necessary to recover the audio signal from it. This process is accomplished in the radio receiver and is called demodulation.