Insights into digital filters made as the sum of two allpass functions

Author

Willson, Alan N., Jr. ; Orchard, H.J.

Author_Institution

Dept. of Electr. Eng., California Univ., Los Angeles, CA, USA

Volume

42

Issue

3

fYear

1995

fDate

3/1/1995 12:00:00 AM

Firstpage

129

Lastpage

137

Abstract

The exact equivalence of the response of a resistance terminated lossless analog lattice filter to that of the algebraic sum of two allpass functions is discussed, culminating in a theorem giving simple necessary and sufficient conditions for a transfer function to be realized in this way. It is shown how various basic analog circuit relationships and properties possess direct counterparts in the realm of digital filtering. The importance of using the well-known characteristic function of analog filter theory for designing digital filters as the sum or difference of two allpass functions is emphasized

Keywords

all-pass filters; digital filters; lattice filters; transfer functions; allpass functions; analog filter theory; characteristic function; digital filters; exact equivalence; resistance terminated lossless analog lattice filter; transfer function; Analog circuits; Delay; Digital filters; Filtering theory; Impedance; Lattices; Reflectivity; Sufficient conditions; Transfer functions; Voltage;

fLanguage

English

Journal_Title

Circuits and Systems I: Fundamental Theory and Applications, IEEE Transactions on

Publisher

ieee

ISSN

1057-7122

Type

jour

DOI

10.1109/81.376877

Filename

376877