Design of CT and CQ filters using approximation and optimization

Author

Levy, Ralph ; Petre, Peter

Author_Institution

R. Levy Associates, La Jolla, CA, USA

Volume

49

Issue

12

fYear

2001

fDate

12/1/2001 12:00:00 AM

Firstpage

2350

Lastpage

2356

Abstract

A new design technique for cascaded triplet (CT) filters has been derived commencing from the well-known Chebyshev all-pole prototype filter. One or more finite frequency poles may be introduced by cross coupling across sets of three nodes, and the filter rematched by a reasonably accurate approximate compensation of the element values. Any general optimizer may then be used to obtain a nearly perfect result without undue concern over convergence failures. A previous similar theory for cascaded quadruplet sections is generalized and may be combined with the CT theory to form filters having both types of sections. The theory is applied to both singly and doubly terminated filters and may include poles on the real axis of the s-plane for delay equalization

Keywords

Chebyshev filters; band-pass filters; cascade networks; circuit optimisation; equivalent circuits; low-pass filters; lumped parameter networks; microwave filters; poles and zeros; Chebyshev all-pole prototype filter; approximate compensation; bandpass filter; cascaded quadruplet filters; cascaded triplet filters; cross coupling; cross-coupled filters; delay equalization; design technique; doubly terminated filters; equivalent circuits; filter optimization; filter synthesis; finite frequency poles; general optimizer; low-pass filter; lumped-element circuit; sets of three nodes; singly terminated filters; Attenuation; Chebyshev approximation; Convergence; Delay; Design optimization; Filtering theory; Frequency; Laboratories; Low pass filters; Prototypes;

fLanguage

English

Journal_Title

Microwave Theory and Techniques, IEEE Transactions on

Publisher

ieee

ISSN

0018-9480

Type

jour

DOI

10.1109/22.971620

Filename

971620