RATIONAL FUNCTION APPROXIMATION OF POLYNOMIALS WITH EQUIRIPPLE ERROR

Abstract

A method was proposed whereby any polynomial can be approximated in an equitable manner by a rational function. The properties and form of this rational function are discussed. Several examples are used to illustrate the theory. Most of these examples are chosen so that the approximating rational function can be identified as a network function part; in particular, the group delay was given special emphasis. The ideal group delay vs. frequency characteristic of filter is a constant. This type of group delay is approximated in an equitable manner. In addition, a numerical scheme is proposed such that from a given crude equitable approximation a more exact solution can be obtained. An ex ample used to illustrate this approach is the problem of compensating the non-constant group delay characteristics of a sharp- cutoff, low pass filter.

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Document Details

Document Type
Technical Report
Publication Date
Feb 01, 1963
Accession Number
AD0402778

Entities

People

  • Deverl Humpherys

Organizations

  • University of Illinois Urbana–Champaign

Tags

Communities of Interest

  • Air Platforms
  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Bandwidth
  • Chebyshev Polynomials
  • Complex Variables
  • Computer Programs
  • Computers
  • Digital Computers
  • Distortion
  • Equations
  • Filters
  • Frequency
  • Frequency Bands
  • Low Pass Filters
  • Polynomials
  • Rational Functions
  • Real Variables
  • Simultaneous Equations
  • Transfer Functions

Fields of Study

  • Mathematics

Readers

  • Calculus or Mathematical Analysis
  • Economics
  • Phased Array Antenna Design.