Howtosignalprocessing
- Do IIR filters have zeros?
- What is the advantage of designing IIR filters using pole-zero plots?
- What are poles and zeros in a filter?
- What implications do poles and zeros have on a digital system stability?
Do IIR filters have zeros?
Designing IIR Notch Filters: requires conjugate zeros on the unit circle (UC) with a poles at the same angle, just inside the UC. The frequency response of the notch is much sharper than a nulling filter which is an FIR filter formed only from the conjugate zeros on the UC.
What is the advantage of designing IIR filters using pole-zero plots?
This is useful for illustrating how the filter causes impulsive inputs to spread out in the time domain. The magnitude and phase plots show and , respectively, plotted with so that the frequency ranges from up to , which are the minimum and maximum frequencies representable in a digital system.
What are poles and zeros in a filter?
Poles and zeros are properties of the transfer function, and in general, solutions that make the function tend to zero are called, well, zeros, and the roots that make the function tend towards its maximum function are called poles.
What implications do poles and zeros have on a digital system stability?
Addition of poles to the transfer function has the effect of pulling the root locus to the right, making the system less stable. Addition of zeros to the transfer function has the effect of pulling the root locus to the left, making the system more stable.
