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Engineering Brief

Generalized Digital Second Order Systems Beyond Nyquist Frequency

Authors: Darabundit, Champ; Wedelich, Russell

AES Convention 149 · Paper 631 · October 2020

Abstract

The Bilinear transform is an established design method for producing digital representations of analog filters. But due to frequency warping inherent in the transform, adequate representation in the digital domain is limited for analog filters designed near or above the Nyquist frequency. Previous work has demonstrated a method for surpassing this design limitation in the case of parametric filters. This paper is an extension of that previous work, and proposes a design methodology for digitally representing any second order system with a center frequency near or above the Nyquist frequency. By repositioning the system poles, this method compensates for the effects of frequency warping, and allows for a more exact digital replication of an analog system’s magnitude response.

Details

Published in
AES Convention 149
AES Convention
149
Paper number
631
Publication date
October 6, 2020
Session subject
Audio Processing
Affiliation
Stanford University, CA, USA; Eventide Inc. Little Ferry, NJ, USA (See document for exact affiliation information.)
Type
Engineering Brief