Amplitude Modulation

Calculations & Observations




Fig.1 AM Wave




Fig.2 Showing the Emax & Emin .

There are some others Figures ( Fig.3 to 5 below ) shown in which the Modulation index are different which will help you in better understanding of how to take Emax & Emin values from the experiment.



Fig.3 AM modulated wave with modulation index of 34%.






Fig.4 AM modulated wave with modulation index of 26%.




Fig.5 AM modulated wave with modulation index of 46%.




Fig.6 Frequency Spectrum of AM modulated wave.

In the Fig.6, the Frequency Spectrum of Amplitude Modulated signal has three peaks shown i.e. at 17300 Hz of 44.36 mV, at 19400 Hz of 0.18 & at 21500 Hz of 0.09. The fundamental frequency detected is at 20 kHz with Fundamental Frequency Power is 0.18. The THD is 0% & SINAD of 2.83 dB.



Fig.7 Power Spectrum of AM modulated wave.

The Power Spectrum in dB scale also shows that in Fig.7, that the Frequency Spectrum has three dominant peaks at different frequency with different power component. The THD is 0% & SINAD of 2.78 dB. The fundamental frequency detected is at 20 kHz with Fundamental Frequency Power is 0.18.