- If all poles and zeros of a PR function are on the unit circle,
then they alternate along the circle. Since this property is
preserved by the bilinear transform, it is true in both the
and planes. It can be viewed as a consequence of the
phase bounds for positive-real functions.
- If is PR, then so is , where the prime denotes differentiation in .
Damping and Tuning Parameters
Minimum Phase (MP) polynomials in