GB1277250A - Improvements in or relating to filter circuits - Google Patents

Improvements in or relating to filter circuits

Info

Publication number
GB1277250A
GB1277250A GB55044/69A GB5504469A GB1277250A GB 1277250 A GB1277250 A GB 1277250A GB 55044/69 A GB55044/69 A GB 55044/69A GB 5504469 A GB5504469 A GB 5504469A GB 1277250 A GB1277250 A GB 1277250A
Authority
GB
United Kingdom
Prior art keywords
section
energized
pair
transmission line
modes
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
GB55044/69A
Inventor
Harold Seidel
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
AT&T Corp
Original Assignee
Western Electric Co Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Western Electric Co Inc filed Critical Western Electric Co Inc
Publication of GB1277250A publication Critical patent/GB1277250A/en
Expired legal-status Critical Current

Links

Classifications

    • HELECTRICITY
    • H03ELECTRONIC CIRCUITRY
    • H03HIMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
    • H03H7/00Multiple-port networks comprising only passive electrical elements as network components
    • H03H7/01Frequency selective two-port networks
    • H03H7/075Ladder networks, e.g. electric wave filters
    • HELECTRICITY
    • H03ELECTRONIC CIRCUITRY
    • H03HIMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
    • H03H7/00Multiple-port networks comprising only passive electrical elements as network components
    • H03H7/01Frequency selective two-port networks
    • H03H7/0115Frequency selective two-port networks comprising only inductors and capacitors

Abstract

1277250 Filters WESTERN ELECTRIC CO Inc 11 Nov 1969 [18 Nov 1968] 55044/69 Heading H1W Filter circuits are constructed using a cascade of bimodal networks all of which are characterized by the same two normal modes, and including means, connecting adjacent pairs of the networks, for converting all of the wave energy from one of the normal modes in one network to the other of the normal modes in the next network. In the Fig. 2 embodiment, each network section 11, 12, 13, 14 is a section of a twinconductor coaxial transmission line having an outer conductor 32, the sections being coupled by phase-inverting transformers 24, 25, and 26 connected between one of the inner conductors and the outer conductor. The filter is energized by a signal source 18 through a hybrid transformer 19 such that, with the source connected to port 1, as shown, conductors 30 and 31 of section 11 are energized in phase i.e. in the symmetric mode, such that section 11 behaves as a length of transmission line of characteristic impedance Z 1 . The signal in conductor 30 undergoes a 180 degree phase shift in transformer 24, such that the signals on the two conductors of section 12 are 180 degrees out of phase i.e. section 12 is energized in the antisymmetric mode, and behaves as a length of transmission line of characteristic impedance Z 2 , where Z 2 is less than Z 1 . Thereafter successive sections are energized alternately in the symmetric and antisymmetric modes, providing characteristic impedances of Z 1 and Z 2 respectively. The filter of Fig. 4 is constructed of a cascade in which each bimodal network section is formed by a pair of quadrature hybrid couplers, the two couplers of each pair being rotated through 90 degrees with respect to one another, so that a pair of ports 3 and 4 symmetrically located with respect to one of the axes of symmetry is coupled to a pair of ports 1 and 3, symmetrically located with respect to the other axis of symmetry. Reference is made to further filters constructed by using a conductively bounded transmission line with discontinuities introduced at locations determined by the different field distributions for the different transmission modes, or employing the different response of gyromagnetic materials to oppositely rotating circularly polarized waves together with an array of longitudinally spaced half waveplates.
GB55044/69A 1968-11-18 1969-11-11 Improvements in or relating to filter circuits Expired GB1277250A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US77639868A 1968-11-18 1968-11-18

Publications (1)

Publication Number Publication Date
GB1277250A true GB1277250A (en) 1972-06-07

Family

ID=25107270

Family Applications (1)

Application Number Title Priority Date Filing Date
GB55044/69A Expired GB1277250A (en) 1968-11-18 1969-11-11 Improvements in or relating to filter circuits

Country Status (5)

Country Link
US (1) US3605044A (en)
BE (1) BE741726A (en)
FR (1) FR2023512A1 (en)
GB (1) GB1277250A (en)
SE (1) SE362323B (en)

Families Citing this family (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3723913A (en) * 1972-05-30 1973-03-27 Bell Telephone Labor Inc Quadrature hybrid coupler using one-port, linear circuit elements
US4390236A (en) * 1981-03-19 1983-06-28 Bell Telephone Laboratories, Incorporated Tunable polarization independent wavelength filter
US8392495B2 (en) * 2009-02-09 2013-03-05 Associated Universities, Inc. Reflectionless filters
GB2496390B (en) * 2011-11-08 2017-06-28 Filtronic Wireless Ltd A filter block and a signal transceiver comprising such a filter block
CN107078708B (en) 2014-06-25 2021-02-09 联合大学公司 Sub-network enhanced reflectionless filter topology
US9923540B2 (en) 2014-11-05 2018-03-20 Associated Universities, Inc. Transmission line reflectionless filters
US10530321B2 (en) 2015-10-30 2020-01-07 Associated Universities, Inc. Deep rejection reflectionless filters
US10263592B2 (en) 2015-10-30 2019-04-16 Associated Universities, Inc. Optimal response reflectionless filters
US10374577B2 (en) 2015-10-30 2019-08-06 Associated Universities, Inc. Optimal response reflectionless filters

Family Cites Families (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3184691A (en) * 1961-11-29 1965-05-18 Bell Telephone Labor Inc Branching hybrid coupler network useful for broadband power-dividing, duplexing and frequency separation
US3252113A (en) * 1962-08-20 1966-05-17 Sylvania Electric Prod Broadband hybrid diplexer
US3192490A (en) * 1962-08-23 1965-06-29 Westinghouse Electric Corp Hybrid network having interconnected center tapped autotransformer windings
US3329884A (en) * 1964-06-08 1967-07-04 Bell Telephone Labor Inc Frequency multiplier utilizing a hybrid junction to provide isolation between the input and output terminals
US3452300A (en) * 1965-08-11 1969-06-24 Merrimac Research & Dev Inc Four port directive coupler having electrical symmetry with respect to both axes
US3423688A (en) * 1965-11-09 1969-01-21 Bell Telephone Labor Inc Hybrid-coupled amplifier
US3444475A (en) * 1967-04-19 1969-05-13 Bell Telephone Labor Inc Broadband hybrid-coupled circuit

Also Published As

Publication number Publication date
DE1957760A1 (en) 1970-05-27
DE1957760B2 (en) 1973-02-01
US3605044A (en) 1971-09-14
BE741726A (en) 1970-04-16
SE362323B (en) 1973-12-03
FR2023512A1 (en) 1970-08-21

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Legal Events

Date Code Title Description
PS Patent sealed [section 19, patents act 1949]
PCNP Patent ceased through non-payment of renewal fee