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EP0501389A2 Expired / Lapsed EP ⏱️ 0.0 years remaining

Bandstop filter

Assignee: Allen Telecom LLC
•
Filing: 1992-02-24
•
Granted: —
•
Expires: 2012-02-24
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Abstract

Abstract A multi-resonator notch filter incorporates a variable impedance transmission line (12) with impedance values going from a relatively low value and increasing upward to a relatively high value then back down to a relatively low value again. A plurality of resonant cavities (22) is coupled to the relatively high central impedance line section (18) of the filter at odd multiples of quarter wavelength intervals. Other resonators (24) can be coupled to lower impedance sections of the transmission line. The locations of selected resonators on the quarter wavelength intervals can be altered thereby increasing and decreasing the nominal quarter wavelength intervals of selected internal pairs by a predetermined amount thereby providing acceptable levels of performance with fewer resonators. <IMAGE>

Inventors

  • 👤 Douglas Ronald Jachowski

Bibliographic Details

Application Number —
Jurisdiction EP
Data Source google_patents
Last Synchronized 2026-11-08 03:10
CPC Classifications
H; H01; H01P; H01P1/00; H01P1/20; H01P1/207; H01P1/208; H01P1/2084; H01P1/209

Claims Analysis

Total Claims: 10
Claim 1
Independent Claim 99 words
A bandstop filter comprising: a common communication line (12) having a first end and a second end (14) including a plurality of quarter wavelength sections therebetween; and a plurality of substantially identical, tunable, dielectric resonators (22) spaced along and coupled to said line with one of said quarter wavelength sections, adjacent to a first resonator from said plurality, increased in length a predetermined amount thereby forming a first modified section and with a second of said quarter wavelength sections, adjacent to a second resonator from said plurality, decreased in length said predetermined amount thereby forming a second modified section.
Claim 2
Dependent Claim 21 words
A filter as in claim 1 with a third member of said plurality of resonators adjacent to said first modified section.
Claim 3
Dependent Claim 19 words
A filter as in claim 2 with a fourth member of said plurality adjacent to said second modified section.
Claim 4
Dependent Claim 43 words
A filter as in claim 1 with said line including a central transmission line section (18) having a characteristic impedance of a first value extending between said ends (14) with first and second impedance transformers (16) coupled thereto at respective of said ends.
Claim 5
Dependent Claim 33 words
A filter as in claim 4 with each of said impedance transformers (16) including an impedance transforming transmission line section with a characteristic impedance of a second value, less than said first value.
Claim 6
Dependent Claim 15 words
A filter as in claim 1 with selected of said resonators tuned to different frequencies.
Claim 7
Dependent Claim 31 words
A filter as in claim 1 with each said resonator including an adjustable mechanism (34) for coupling to said line (12) with selected of said resonators coupled thereto in varying degrees.
Claim 8
Dependent Claim 33 words
A filter as in claim 1 with each said resonator including means for coupling to a respective section of said line and with all of said modified sections reduced a predetermined compensating amount.
Claim 9
Dependent Claim 17 words
A filter as in claim 1 with said plurality of resonators having an even number of resonators.
Claim 10
Dependent Claim 46 words
A filter as in claim 6 with a stopband centered about a selected center frequency and wherein selected of said resonators are tuned to respective frequencies below the center frequency and wherein different selected of said resonators are tuned to respective frequencies above the center frequency.

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