Two computer programs for the sensitivity analysis of higher order filters
Soderstrand, John Lathrop · OSTI OAI (U.S. Department of Energy Office of Scientific and Technical Information) · 1974
A typical filter exhibits a transfer function in the frequency domain which is, as a function of the complex frequency variable (Laplace variable) s, a numerator polynomial (the zeros of which are called zeros) divided by a denominator polynomial (the zeros of which are called poles). Changes in network elements (e.g. the values of resistors, capacitors, inductors, and amplifier gains) cause changes in the coefficients of these transfer function polynomials. The two computer programs described in this report can be used to determine the relationship between these changes and the changes they introduce in the position of the poles and zeros. The poles of the networks are usually more important than the zeros and are grouped together into complex conjugate pairs which are defined by their resonant frequency / omega /sub o/ and quality factor Q. The specific problem solved by the computer programs outlined here is that of finding the relationship between changes in omega /sub o/ and Q and changes in the coefficients of the transfer function denominator. The first program described is a FORTRAN IV program called CASAHOF (Computer Aided Sensitivity Analysis of Higher Order Filters), written for the GP250 interactive graphics console at Sandia Laboratories, Livermore.more » The other program described is a REDUCE II program which finds the algebraic relationships between the omega /sub o/ and Q changes (sensitivities) and the coefficient changes (sensitivities). (auth)« less