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Question
The carrier wave is given by
C(t) = 2sin(8πt) volt.
The modulating signal is a square wave as shown. Find modulation index.
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Solution
Modulation index (μ) is the ratio of the amplitude of the modulating signal to the amplitude of the carrier wave.
The generalised equation of a carrier wave is given below:
c(t) =Acsinωct
The generalised equation of a modulating wave is given below:
cm(t)=Acsinωct+μAcsinωmtsinωct
Here, μ is defined as `A_m/A_c`
On comparing this with the equations of carrier wave and modulating wave, we get:
Amplitude of modulating signal, Am=1 V
Amplitude of carrier wave, Ac=2 V
`:.mu=A_m/A_c=1/2=0.5`
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