Patent US5392011A successfully refreshed from Google Patents.
US5392011A
Expired / Lapsed
US
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Tunable filter having capacitively coupled tuning elements
Assignee: Motorola Solutions Inc
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Filing: 1992-11-20
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Granted: 1995-02-21
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Expires: 2012-11-20
Abstract
Abstract A tunable filter (100) is provided including a first resonator (110) and a second resonator (120). The bandwidth of the tunable filter is maintained constant by providing purely inductive coupling (114) between the first and the second resonators (110 and 120). The first and the second resonators (110 and 120) include tuning elements (108-109 and 118-119) which are second coupled to each other by means of a capacitor (130) to improve image rejection performance of the tunable filter (100).
Inventors
- 👤 Richard C. Li
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 15:40
CPC Classifications
H; H03; H03J; H03J3/00; H03J3/02; H03J3/06; H03J3/08; H03H; H03H7/00; H03H7/01; H03H7/0115; H03H7/17; H03H7/1741; H03H7/175; H03H7/1758; H03H2210/00; H03H2210/02; H03H2210/025
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
56 words
A tunable filter, comprising: a first resonator having a series resonant circuit including a first tuning element and coupled between two shunted inductors; a second resonator having a second tuning element; coupling means for coupling the first resonator to the second resonator; a capacitor for capacitively coupling the first tuning element to the second tuning element.
Claim 2
Dependent Claim
56 words
A tunable filter, comprising: a first resonator having a series resonant circuit including a first tuning element and coupled between two shunted inductors; a second resonator having a second tuning element; coupling means for coupling the first resonator to the second resonator; a capacitor for capacitively coupling the first tuning element to the second tuning element.
Claim 3
Dependent Claim
16 words
The tunable filter of claim 1, wherein said coupling means comprises a purely inductive coupling means.
Claim 4
Dependent Claim
23 words
The tunable filter of claim 1, wherein at least one of said first tuning element and said second tuning element comprise back-to-back varactors.
Claim 5
Dependent Claim
19 words
The tunable filter of claim 1, wherein said series resonant circuit comprises the first tuning element and an inductor.
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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) | 1998-02-20 | 1998-08-22 | 1999-02-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-02-20 | 2002-08-22 | 2003-02-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-02-20 | 2006-08-22 | 2007-02-21 | $7700.00 | Window Closed / Lapsed |