Question

What is the value of stop band ripple in dB?

(a) -20log(1-δS)

(b) -20log(δS)

(c) 20log(1-δS)

(d) None of the mentioned

This question was addressed to me by my school teacher while I was bunking the class.

This intriguing question originated from Specifications and Classification of Analog Filters topic in division Digital Filters Design of Digital Signal Processing

Answer 1

Correct option is (b) -20log(δS)

For explanation I would say: δS is known as the stop band attenuation, and its value in dB is given as -20log(δS).