The Z transform of a 4 pole (2 complex conjugate pairs) system is shown below:-

The properties of the transfer function in the Z domain of a system, with the 4 poles as shown in the above eqn, is shown in the applet below for z within the unit circle. Fn = 0 shows the Magnitude, Fn = 1 shows the Phase, Fn = 2 shows the Real part and Fn = 3 shows the Imaginary part of the transfer function.

Copyright 2008 © Cuthbert A. Nyack.