Robust op amp circuit realizations using tridiagonal state space forms

The standard controllable and observable canonical realizations have A-matrices whose eigenvalue locations are highly sensitive to small perturbations to the nonzero entries of the A-matrix that correspond to the coefficients of the characteristic polynomial. On the other hand, the eigenvalue locations of tri-diagonal A-matrices are relatively insensitive to similar perturbations. Given a SISO transfer function with known poles and zeros, this paper details an approach to state space realizations with tridiagonal A-matrices using a genetic algorithm and the equivalence of the realization with a canonical form.