Z Transform 4 Zeros Frequency Response.

Cuthbert Nyack
Applet shows the Impulse and Frequency response of a system with complex conjugate zeros at z1 e±jz1f p/180 and z2 e±jz2f p/180, 4 poles are included at the origin to make the impulse response zero for t < 0.
Vi and Vg changes gain of impulse and frequency response.

eg parameters (1.0, 100.0, 1.0, 148.0, NA, NA, NA, 0.35, 70, 0.45)
Applet shows a basic low pass configuration with zeros in the stop band. All zeros are on the unit circle, the impulse response is FINITE and SYMMETRIC and the phase is LINEAR. Moving any of the zeros away from the unit circle by changing z1 or z2 results in the impulse response becoming asymmetric and the phase becoming nonlinear

eg parameters (1.0, 30.0, 1.0, 80.0, NA, NA, NA, 0.5, 375, 0.40)
Applet shows a basic high pass configuration with zeros in the stop band. The impulse response is still symmetric but alternates in sign.

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Copyright 2008 © Cuthbert A. Nyack.