Question

What is the error in magnitude at the frequency ωk?

(a) G.A(ωk) + Ad(ωk)

(b) G.A(ωk) – Ad(ωk)

(c) G.A(ωk) – A(ωk)

(d) None of the mentioned

I have been asked this question by my school principal while I was bunking the class.

I would like to ask this question from Design of IIR Filters in Frequency Domain in portion Digital Filters Design of Digital Signal Processing

Answer 1

The correct option is (b) G.A(ωk) – Ad(ωk)

To explain: The error in magnitude at the frequency ωk is G.A(ωk) – Ad(ωk) for 0 ≤ |ω| ≤ π, where Ad(ωk) is the desired magnitude response at ωk.