Tabular Method for Determining Root Distribution of Delta-Operator Formulated Real Polynomials

Kamal Premaratne, Eliahu I. Jury

Research output: Contribution to journalArticle

18 Scopus citations


A tabular method for the investigation of real polynomial root distribution with respect to the circle |c+1/Δ |=1Δ in the complex plane is presented. Such a procedure is useful in stability considerations of δ-operator formulated discrete-time systems with sampling time Δ, in particular, when the characteristic polynomial contains literal coefficients. We show that, direct verification of stability may be preferable over techniques that utilize transformations when the sampling frequency is fast relative to the system bandwidth. In addition, as sampling frequency increases, the relationship with the well known Routh-Hurwitz table becomes apparent.

Original languageEnglish (US)
Pages (from-to)352-355
Number of pages4
JournalIEEE Transactions on Automatic Control
Issue number2
StatePublished - Feb 1994


ASJC Scopus subject areas

  • Control and Systems Engineering
  • Computer Science Applications
  • Electrical and Electronic Engineering

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