(1) Embedded Signal Processing Laboratory,
Department of Electrical and Computer Engineering,
Engineering Science Building,
The University of Texas at Austin,
Austin, TX 78712-1084 USA

magesh@ece.utexas.edu -
bevans@ece.utexas.edu -
gzara@ece.utexas.edu

(2) School of Electrical Engineering,
University of Belgrade,
Bulevar Revolucije 73,
11000 Belgrade, Yugoslavia

etosicde@ubbg.etf.bg.ac.yu -
lutovac@iritel.bg.ac.yu

(Miroslav Vlcek): Why |H|=1 when the filter order is even?**Question**(Miroslav Vlcek): Do we assume odd order?**Question**

: No. The approach works for even and odd orders. We give the formula for the even case.**Answer**(Miroslav Vlcek): What is the magnitude response type after optimization?**Question**

: It really depends on the cost function, constraints, and initial guess.**Answer**(Miroslav Vlcek): What is the group delay?**Question**

: The derivative of the phase response.**Answer**(Akinori Nishihara): Why do you use Q-factor [quality factor] as an implementation property?"**Question**

: The Q-factor is a technology-independent measure of the sensitivity of a real pole or conjugate pole pair to perturbation (e.g. roundoff or truncation). The larger the Q-factor, the more likely the pole will oscillate.**Answer**

: Nishihara published a 1998 paper in**Note***Electronics Letters*, in which he defines a Q-factor for digital IIR filters.(Andre Gunst): Do you have similar software for analog filters? If yes, is it user friendly?**Question**

: Yes. See the**Answer**- N. Damera-Venkata and B. L. Evans,
"An
Automated Framework for Multicriteria Optimization of Analog Filter
Designs",
*IEEE Transactions on Circuits and Systems II: Analog and Digital Signal Processing*, vol. 46, no. 8, pp. 981-990, Aug. 1999. - Filter Optimization Packages for Matlab and Mathematica

- N. Damera-Venkata and B. L. Evans,
"An
Automated Framework for Multicriteria Optimization of Analog Filter
Designs",

Last Updated 02/19/01.