Finding filter type from Pole/Zero plots.

How can you tell by looking at the pole/zero plot on the Z plane what type of filter you are looking at? i.e LPF, HPF, BP, BS etc…

I can find this info for All Pass / Min Phase plots, but I can’t find any info on how these plots relate to different fiolter types.

Any idea?

Low pass filters will have the pole closer to the origin than the zeros. They may not have zeros at all.

High pass filters will have the zeros close the origin and will probably have at least one on the origin.

Bandpass filters will have zeroes close to the origin and some poles farther away then more poles even farther away.

What is BS?


BS as band stop. Then reverse the poles and zeros from the bandpass.