An amplitude modulated wave is as shown in Fig. 15.4. Calculate (i) the percentage modulation, (ii) peak carrier voltage and, (iii) peak value of information voltage.

Question

Philoid · Accepted Answer

From the figure, we have

Maximum voltage,

Minimum voltage,

We know that

where V_c and V_m are the peak voltage (voltage amplitude) of carrier signal and message signal respectively.

Adding equation (1) and equation (2), we get

Subtracting (2) from (1), we get

(i) Now, the modulation index is given by:

(ii) Peak carrier voltage ,

(iii) Peak value of information,