Patent US4365221A successfully refreshed from Google Patents.
US4365221A
Expired / Lapsed
US
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Helical resonator filter with dielectric apertures
Assignee: Motorola Solutions Canada Inc
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Filing: 1981-03-30
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Granted: 1982-12-21
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Expires: 2001-03-30
Abstract
Abstract A helical resonator filter includes several helical coils, each grounded at one end and free at the other and enclosed within a cavity. The coils are coupled to each other electromagnetically through apertures in the conductive walls separating the resonator cavities from each other. A dielectric member is inserted into the apertures to increase coupling between adjacent coils to increase the bandwidth of the filter.
Inventors
- 👤 Peter Vizmuller
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 03:11
CPC Classifications
B; B03; B03C; B03C1/00; H; H01; H01P; H01P1/00; H01P1/20; H01P1/201; H01P1/205
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
67 words
A helical resonator filter comprising: a plurality of conductive helical coils; a conductive shell having a plurality of cavities, each cavity including one of said helical coils and separated by conductive walls, the wall between adjacent cavities having an aperture for providing electromagnetic coupling between adjacent helical coils; and a dielectric member inserted in each of the apertures to increase the electromagnetic coupling between adjacent helical coils.
Claim 2
Dependent Claim
67 words
A helical resonator filter comprising: a plurality of conductive helical coils; a conductive shell having a plurality of cavities, each cavity including one of said helical coils and separated by conductive walls, the wall between adjacent cavities having an aperture for providing electromagnetic coupling between adjacent helical coils; and a dielectric member inserted in each of the apertures to increase the electromagnetic coupling between adjacent helical coils.
Claim 3
Dependent Claim
34 words
The helical resonator filter according to claim 1, wherein each dielectric member is comprised of a block of dielectric material that is substantially the same size as the aperture in which it is located.
Claim 4
Dependent Claim
46 words
The helical resonator filter according to claim 1, wherein each dielectric member is comprised of a block of dielectric material that is substantially the same size as the aperture in which it is located and that physically contacts the helical coils between which it is located.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-12-20 | 1986-06-21 | 1986-12-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-12-20 | 1990-06-21 | 1990-12-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-12-20 | 1994-06-21 | 1994-12-21 | $7700.00 | Window Closed / Lapsed |