Patent US3891948A successfully refreshed from Google Patents.
US3891948A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Microwave filter using hybrid circuit and resonators
Assignee: Thales SA
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Filing: 1974-06-25
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Granted: 1975-06-24
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Expires: 1994-06-25
Abstract
Abstract A first one of the two ports of a first pair of conjugate ports of a directional coupler forms the input of the filter. Two line sections, one short-circuited, the other open, are respectively coupled to the conjugate ports of the second pair. Two resonators tuned to a frequency Fo are respectively coupled in parallel to the two line sections at a distance of d/8 (d: wavelength corresponding to the frequency Fo) of the ends of these two line sections opposite those coupled to the directional coupler. According to whether the frequency of an input signal is Fo or not, this signal is collected at the second port of the first pair, or returned to the input port.
Inventors
- 👤 Michel Destrade
- 👤 Jean-Lucin Out Vassort
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 17:51
CPC Classifications
H; H01; H01P; H01P1/00; H01P1/20; H01P1/213; H01P1/2133; H01P1/2138
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
74 words
A branching filter comprising: a hybrid circuit having two pairs of conjugate ports; two line sections having respective first ends connected respectively to the ports of one and the same pair of conjugate ports and respective second ends one of which is open and the other short-circuited; and two resonators tuned to the same frequency Fo and respectively coupled in parallel to said two line sections at the same distance from said second ends.
Claim 2
Dependent Claim
74 words
A branching filter comprising: a hybrid circuit having two pairs of conjugate ports; two line sections having respective first ends connected respectively to the ports of one and the same pair of conjugate ports and respective second ends one of which is open and the other short-circuited; and two resonators tuned to the same frequency Fo and respectively coupled in parallel to said two line sections at the same distance from said second ends.
Claim 3
Dependent Claim
34 words
A branching filter as claimed in claim 1, wherein said distance is equal to (2k+1) d/8, where k is a non negative integer and where d is the wavelength corresponding to the frequency Fo.
Claim 4
Dependent Claim
27 words
A branching filter as claimed in claim 1, wherein said hybrid circuit is a 3-decibel directional coupler and wherein said two line sections have the same length.
Claim 5
Dependent Claim
130 words
A branching filter as claimed in claim 1, wherein each of said resonators has a wall provided with two holes located opposite each other, wherein each of said two line sections comprises two portions of a coaxial line, the two portions of a line section being respectively located in front of the two holes of the resonators coupled to this line section and having respective external conductors connected to the wall of this same resonator and respective internal conductors respectively passing through the two holes of the wall of this same resonator, and wherein said filter comprises two coupling means, respectively located inside said two resonators, for coupling said line sections to said resonators, said two internal conductors of each line section being connected together through the corresponding coupling means.
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) | 1978-06-23 | 1978-12-23 | 1979-06-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-06-23 | 1982-12-23 | 1983-06-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-06-23 | 1986-12-23 | 1987-06-24 | $7700.00 | Window Closed / Lapsed |