Sampling frequency in Amplitude Modulation
Q. A 3 GHz carrier is DSB SC modulated by a signal with maximum frequency of 2 MHz. The minimum sampling frequency required for the signal so that the signal is ideally sampled is- Published on 12 Oct 15a. 4 MHz
b. 6 MHz
c. 6.004 GHz
d. 6 GHz
ANSWER: 6.004 GHz
According to Nyquist sampling criteria, a bandlimited signal should be sampled equal to greater than twice the maximum frequency of the signal.
Here, the spectrum obtained after the conversion has a maximum frequency of 3000MHz + 2MHz = 3002MHz. So the sampling frequency required to prevent aliasing is 6004MHz i.e., 6.004GHz.