US4490699A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Intermediate frequency band-pass filter
Assignee: Alps Alpine Co Ltd
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Filing: 1983-05-26
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Granted: 1984-12-25
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Expires: 2003-05-26
Abstract
Abstract An intermediate frequency band-pass filter for providing a pass band, comprising a frame forming a hollow surrounded region, a shield plate mounted in the frame and dividing the hollow surrounded region into two spaces, the shield plate having a coupling window, and two resonators disposed respectively in the spaces and coupled through the coupling window, the shield plate having in an edge thereof a step serving as a trap which provides a frequency suppression capability in the vicinity of the pass band of the filter.
Inventors
- 👤 Hiroyuki Yanagida
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 10:40
CPC Classifications
H; H01; H01P; H01P1/00; H01P1/20; H01P1/201; H01P1/205; H01P1/2053
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
85 words
An intermediate frequency band-pass filter for providing a pass band, comprising a frame forming a hollow surrounded region, a shield plate mounted in said frame and dividing said hollow surrounded region into two spaces, said shield plate having a coupling window, and two resonators disposed respectively in said spaces and coupled through said coupling window, said shield plate having in an edge thereof a step serving as a trap which provides a frequency suppresion capability in the vicinity of the pass band of the filter.
Claim 2
Dependent Claim
85 words
An intermediate frequency band-pass filter for providing a pass band, comprising a frame forming a hollow surrounded region, a shield plate mounted in said frame and dividing said hollow surrounded region into two spaces, said shield plate having a coupling window, and two resonators disposed respectively in said spaces and coupled through said coupling window, said shield plate having in an edge thereof a step serving as a trap which provides a frequency suppresion capability in the vicinity of the pass band of the filter.
Claim 3
Dependent Claim
21 words
An intermediate frequency band-pass filter according to claim 1, wherein said edge of said shield plate is an upper edge thereof.
Claim 4
Dependent Claim
29 words
An intermediate frequency band-pass filter according to claim 1, wherein said step is in the form of a rectangular recess cut out of said edge of said shield plate.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-12-25 | 1988-06-25 | 1988-12-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-12-25 | 1992-06-25 | 1992-12-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-12-25 | 1996-06-25 | 1996-12-25 | $7700.00 | Window Closed / Lapsed |