FPGA Central

Trasfer function completely discribe the input output relationship of an LTI
system. Using Matlab command, zplane(num, den) I plotted graph of Zeros and
Poles. I got 3 poles, one at origin of unit cricle, 2nd at intersecting
point of positive real axis and unit circle and 3rd is at intersecting point
of negative real axis and unit cricle. 768 zeros all sorrounding unit
cricle but not exactly on unit circle. How can I best understand with this
information the behavior of system ??

thanks !!

Abdul wrote:
> Trasfer function completely discribe the input output relationship of an LTI
> system. Using Matlab command, zplane(num, den) I plotted graph of Zeros and
> Poles. I got 3 poles, one at origin of unit cricle, 2nd at intersecting
> point of positive real axis and unit circle and 3rd is at intersecting point
> of negative real axis and unit cricle. 768 zeros all sorrounding unit
> cricle but not exactly on unit circle. How can I best understand with this
> information the behavior of system ??

Consider them as deformations of a rubber sheet on the
complex plane. Poles pull up teats and zeros push them
down. If you transform the sheet by taking the logarithm of
the values on it measured orthogonal to the complex plane,
project a tube up from the unit circle, then the
intersection of that tube with the transformed sheet is the
log magnitude of the transfer function. As you go around
it, the frequency increaes from zero to half the sample rate.


Bob
--

"Things should be described as simply as possible, but no
simpler."

A. Einstein