Question

What happens when modulation index is greater than one?

Answer 1

1. Modulation index is the ratio of amplitude of modulating signal to the amplitude of carrier wave signal.
   $$\begin{gathered} \mathrm{modulation}\mathrm{index}=\frac{\mathrm{Amplitude}\mathrm{of}\mathrm{modulating}\mathrm{signal}}{\mathrm{Amplitude}\mathrm{of}\mathrm{carrier}\mathrm{wave}} \\ \mathrm{m}=\frac{{\mathrm{A}}_{\mathrm{m}}}{{\mathrm{A}}_{\mathrm{C}}} \end{gathered}$$
2. If modulation index is greater the one it is called over modulation.
3. The over modulated signal is distorted.
4. When over modulation occurs then the envelope of the output waveform is distorted.
5. When modulation index is greater than one it means the modulating signal go beyond of its desired value and produce $100\%$modulation of the carrier wave.