US5392011A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Tunable filter having capacitively coupled tuning elements
Assignee: Motorola Solutions Inc
•
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 15:34
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.
References Cited (Backward Citations)
US1227113A
Cited
US3049682A
Cited
US3534301A
Cited
US3798578A
Cited
US4264881A
Cited
US4157517A
Cited
US4430630A
Cited
JPS59111412A
Cited
US4578656A
Cited
US4661790A
Cited
US4609829A
Cited
US4586007A
Cited
US4601062A
Cited
US4992759A
Cited
US4785271A
Cited
US4839617A
Cited
JPH0260303A
Cited
US5021757A
Cited
US4940955A
Cited
US5150085A
Cited
EP0413211A2
Cited
US5066933A
Cited
US5138288A
Cited
US5241291A
Cited
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 |