mvaibhav
Junior Member
Offline
Posts: 10
|
Hi, I need an intuitive explanation of how complex poles in the s-plane appear or affect the frequency characteristics of, let's say a low-pass filter. For real poles on the negative real axis, I can simply say that the frequency response will roll off at a slope of -20 dB/decade for every such pole/frequency. How can I map the complex poles on the real frequency axis?? e.g., for Butterworth filter, it has maximally flat passband whereas chebyshev has ripple in the pass band. Why do we use complex poles at all to design filters (apart from a better step response)??
many thanks.
regards, vaibhav
|