Consider the following statements with respect to the bilinear transformation method of digital filter design:
1. It preserves the number of poles and thereby the order of the filter.
2. It maintains the phase response of the analog filter.
3. The impulse response of the analog filter is not preserved.
Which of the above statements are correct?
1. 1, 2 and 3
2. 1 and 2 only
3. 1 and 3 only
4. 2 and 3 only