For AR HP filter
- zeros, to the right of the imaginary axis
- poles outside the unit-circle
- zeros on the real axis
- poles, to the left of the imaginary axis
Apparently, the right answer is (4). Why?
We did learn in class some properties of the zeros and poles, and I probably need to relate it to the fact that it's a AR HP filter.
I'd be glad for your help.
Thanks!
EDIT:
I know that AR is an all-poles filter so it must be (1) or (4). What is the meaning of the position of the pole with relation to the imaginary axis?
EDIT 2:
Is it because the large $\omega$'s (frequencies as angles of the unit circle) are at the left side of the imaginary axis and so we get an HP filter?