Question

Using which of the following methods, a digital IIR filter can be directly designed?

(a) Pade approximation

(b) Least square design in time domain

(c) Least square design in frequency domain

(d) All of the mentioned

I got this question in an online interview.

This is a very interesting question from Pade Approximation Method topic in division Digital Filters Design of Digital Signal Processing

Answer 1

Correct option is (d) All of the mentioned

For explanation I would say: There are several methods for designing digital filters directly. The three techniques are Pade approximation and least square method, the specifications are given in the time domain and the design is carried in time domain. The other one is least squares technique in which the design is carried out in frequency domain.