FREQUENCY MODULATION (F.M.)

The modulation of the frequency of the R.F./carrier wave based on the A.F. is termed as Frequency Modulation.

In this type of Modulation, when the amplitude of the modulating wave increases, the frequency of the R.F. wave increases

&

When the amplitude of the modulating wage decreases, the frequency of the R.F. wave decreases

CHARACTERISTICS OF FREQUENCY MODULATION

ADVANTAGES

• Transmitter is simpler whereas receiver is complicated in design.

• Free from static and noise interferences.

DISADVANTAGES

• For same transmission, power range is lesser

FREQUENCY MODULATION IS ALWAYS BETTER THAN  AMPLITUDE MODULATION

The reason is simple,

When an A.M. wave enters in a field of high electrical energy or power, the E.M. waves generated by them distorts the amplitude of the wave and when the demodulator tries to detect the information related wave, it too detects the distorted waves and the resultant output is noisy.

But,

When a F.M. wave enters the field of high electrical energy or power, the E.M. waves generated by themdefinitely distorts the amplitude of the wave but the frequency remains constantand hence the demodulator detects the clear wave which is then amplified to be supplied to the audio device.