Question 10.9: Amplitude Distortion The input signal to a certain amplifier...
Amplitude Distortion
The input signal to a certain amplifier contains two frequency components and is given by
v_i(t) = 3 \cos(2000\pi t) – 2 \cos(6000\pi t)
The gain of the amplifier at 1000 Hz is 10 \underline{/0}^\circ, and the gain at 3000 Hz is 2.5 \underline{/0}^\circ. Plot the input waveform and output waveform to scale versus time.
The first term of the input signal is at a frequency of 1000 Hz, so it experiences a gain of 10 \underline{/0}^\circ, whereas the second term of the input is at a frequency of 3000 Hz, so the gain for it is 2.5 \underline{/0}^\circ. Applying these gains and phase shifts to the terms of the input signal, we find the output:
v_o(t)=30 \cos(2000 \pi t)-5\cos(6000 \pi t)
Plots of the input and output waveforms are shown in Figure 10.26. Notice that the output waveform has a different shape than the input waveform because of amplitude distortion.
