Question 11.9: 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
vi(t) = 3 cos(2000πt) – 2 cos(6000πt)
The gain of the amplifier at 1000 Hz is 10∠0°, and the gain at 3000 Hz is 2.5∠0°. 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∠0° ,whereas the second term of the input is at a frequency of 3000 Hz, so the gain for it is 2.5∠0°.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 11.26. Notice that the output wave form has a different shape than the input wave form because of amplitude distortion.
