We can easily calculate the Bandwidth of the Amplitude modulated wave from its spectrum-. Df 75 KHz fm 5000 Hz BWFM 2 75 50001000 KHz 1600 KHz. Using the formula above this means that the deviation ratio is 75 15 5.
For example if the carrier voltage is 8 V and the modulating information signal voltage is 65 V then the modulation index will be 08125.
In other words b represents a way to express the peak deviation frequency as a multiple of the maximum modulating frequency f m ie. Mt Amcos2pfmt and the carrier signal be ct Accos2pfct Where Am and Ac are the amplitude of the modulating signal and the carrier signal respectively. Percent Modulation of FM Wave. Df 75 KHz fm 10000 Hz BWFM 2 75 100001000 KHz 1700 KHz.