Question

The principle behind Sigma-Delta ADC is oversampling.

(a) True

(b) False

I had been asked this question in an interview for internship.

Origin of the question is ADC Tradeoffs topic in section Technology Tradeoffs in Software Defined Radio of Cognitive Radio

Answer 1

Right option is (a) True

To elaborate: It can be observed from the expression SNR=6.02*B+1.76+10log((frac{f_s}{2f_{max}})), as the sampling frequency increases, SNR increases. This is the principle behind Sigma-Delta ADC. The amount of oversampling is given by the ratio of sampling frequency to Nyquist frequency.