A carrier wave of peak voltage 12V is used to transmit a message signal. What should be the peak voltage of the modulating signal in order to have a modulation index of 75%?

Question

Philoid · Accepted Answer

Amplitude of the carrier wave, A_c = 12 V

Modulation index, m = 75% = 0.75 (unitless as a ratio)

Amplitude of the modulating wave = A_m

We know for modulation index:

m = A_m/A_c

⇒ A_m = mA_c

⇒ A_m = (0.75 × 12) V = 9V