A. The carrier frequency exceeds the message bandwidth in conventional use.B. Overmodulation causes envelope distortion.C. A coherent detector can demodulate DSB-SC.D. An envelope detector directly recovers any DSB-SC signal.
Correct Answer: A|B|C
Explanation:
DSB-SC lacks a transmitted carrier for simple envelope detection.
A. Input currents are zero.B. Open-loop gain is treated as infinite.C. The input terminals are at equal voltage under linear operation.D. Output resistance is infinite.
A. The carrier frequency exceeds the message bandwidth in conventional use.B. Overmodulation causes envelope distortion.C. A coherent detector can demodulate DSB-SC.D. An envelope detector directly recovers any DSB-SC signal.
Correct Answer: A|B|C
Explanation:
DSB-SC lacks a transmitted carrier for simple envelope detection.
A. Sampling above twice the highest frequency can avoid aliasing.B. Aliasing is spectral overlap after sampling.C. An anti-aliasing filter is placed before the sampler.D. Sampling frequency has no effect on reconstruction.
Correct Answer: A|B|C
Explanation:
Reconstruction depends critically on sampling rate.
A. Input currents are zero.B. Open-loop gain is treated as infinite.C. The input terminals are at equal voltage under linear operation.D. Output resistance is infinite.
