1. In case of frequency modulation the change in amplitude may be due to noise. If we make use of amplitude limiters in FM receivers then we can completely vanish this noise effect.
2. FM waves are waves having constant amplitude. These are independent of the modulation. So, due to this the power transmission of these waves is also constant. The power transmission of FM waves is better than that of the AM signals.
3. In FM signals, all the transmitted power can be used, but in AM wave the transmission carriers contain most of the power. So, complete use of power is not possible.
4. In FM wave’s noise can be controlled by increasing the deviation up to some amount. This is impossible in case of AM waves.
5. VHF and UHF are the bands of FM broadcasting. In these bands noise effect is very less. But on the other hand bands of AM broadcasting such as MF and HF has higher effects.
6. Co-channel interference can be reduced by using some space wave in FM broadcasting.
The major disadvantages of FM are:
1. Complex apparatus is used to transmit and receive the FM wave.
2. FM waves needs 10 times larger channel width than that of the AM waves.
3. The reception area of FM waves is less than that of AM waves. Due to this wide area communication using the Fm waves is not possible.
